,,the ,,chemistry ,,of ,,hat ,,manufacturing ,,lectures ,,delivered ,,before ,,the ,,hat ,,manufacturers' ,,association ,,by ,,watson ,,smith1 ,f4,c4,s41 ,f4,i4,c4 ,,then ,,lecturer ,,in ,,chemical ,,technology ,,in ,,the ,,owens ,,college1 ,,manchester ,,and ,,lecturer ,,of ,,the ,,victoria ,,university ,,revised ,,and ,,edited ,,by ,,albert ,,shonk ,,with ,,sixteen ,,illustrations ,,london ,,scott1 ,,greenwood ,,son ,,the ,,hatters' ,,gazette ,,offices #h ,,broadway1 ,,ludgate ,,hill1 ,e4,c4 ,,canada3 ,,the ,,copp ,,clark ,,co4 ,,ltd41 ,,toronto ,,united ,,states3 ,d4 ,,van ,,nostrand ,,co41 ,,new ,,york #aijf ,all rights remain with ,scott1 ,greenwood ,son ,transcriber's ,note3 ,underscores around words indicates italics while an underscore and curly brackets in an equation indicates a subscript4 ,,preface ,the subject-matter in this little book is the substance of a series of ,lectures delivered before the ,hat ,manufacturers' ,association in the years #ahhg and #ahhh4 ,about this period1 owing to the increasing difficulties of competition with the products of the ,german ,hat ,manufacturers1 a deputation of ,hat ,manufacturers in and around ,manchester consulted ,sir ,henry ,e4 ,roscoe1 ,f4,r4,s41 then the ,professor of ,chemistry in the ,owens ,college1 ,manchester1 and he advised the formation of an ,association1 and the appointment of a ,lecturer1 who was to make a practical investigation of the art of ,hat ,manufacturing1 and then to deliver a series of lectures on the applications of science to this industry4 ,sir ,henry ,roscoe recommended the writer1 then the ,lecturer on ,chemical ,technology in the ,owens ,college1 as lecturer1 and he was accordingly appointed4 ,the lectures were delivered with copious experimental illustrations through two sessions1 and during the course a patent by one of the younger members became due1 which proved to contain the solution of the chief difficulty of the ,british felt-hat manufacturer 7see pages #ff-fh74 ,this remarkable coincidence served to give especial stress to the wisdom of the counsel of ,sir ,henry ,roscoe1 whose response to the appeal of the members of the deputation of #ahhg was at once to point them to scientific light and training as their only resource4 ,in a letter recently received from ,sir ,henry 7#aijf71 he writes3 ,i agree with you that this is a good instance of the direct money value of scientific training1 and in these days of 'protection' and similar subterfuges1 it is not amiss to emphasise the fact4 ,it is thus gratifying to the writer to think that the lectures have had some influence on the remarkable progress which the ,british ,hat ,industry has made in the twenty years that have elapsed since their delivery4 ,these lectures were in part printed and published in the ,hatters' ,gazette1 and in part in newspapers of ,manchester and ,stockport1 and they have here been compiled and edited1 and the necessary illustrations added1 etc41 by ,mr4 ,albert ,shonk1 to whom ,i would express my best thanks4 ,,watson ,,smith4 ,,london1 ,april #aijf4 ,,contents ,,lecture ,,page ,i4 ,,textile ,,fibres1 ,,principally ,,wool1 ,,fur1 ,,and ,,hair #a ,,ii4 ,,textile ,,fibres1 ,,principally ,,wool1 ,,fur1 ,,and ,,hair--continued #ah ,,iii4 ,,water3 ,,its ,,chemistry ,,and ,,properties2 ,,impurities ,,and ,,their ,,action2 ,,tests ,,of ,,purity #bi ,,iv4 ,,water3 ,,its ,,chemistry ,,and ,,properties2 ,,impurities ,,and ,,their ,,action2 ,,tests ,,of ,,purity--continued #ch ,v4 ,,acids ,,and ,,alkalis #di ,,vi4 ,,boric ,,acid1 ,,borax1 ,,soap #eg ,,vii4 ,,shellac1 ,,wood ,,spirit1 ,,and ,,the ,,stiffening ,,and ,,proofing ,,process #fb ,,viii4 ,,mordants3 ,,their ,,nature ,,and ,,use #fi ,,ix4 ,,dyestuffs ,,and ,,colours #gi ,x4 ,,dyestuffs ,,and ,,colors--continued #hi ,,xi4 ,,dyeing ,,of ,,wool ,,and ,,fur2 ,,and ,,optical ,,properties ,,of ,,colours #ajj ,,index #aag ,,the ,,chemistry ,,of ,,hat ,,manufacturing ,,lecture ,i ,,textile ,,fibres1 ,,principally ,,wool1 ,,fur1 ,,and ,,hair ,vegetable ,fibres4--,textile fibres may be broadly distinguished as vegetable and animal fibres4 ,it is absolutely necessary1 in order to obtain a useful knowledge of the peculiarities and properties of animal fibres generally1 or even specially1 that we should be1 at least to some extent1 familiar with those of the vegetable fibres4 ,i shall therefore have1 in the first place1 something to tell you of certain principal vegetable fibres before we commence the more special study of the animal fibres most interesting to you as hat manufacturers1 namely1 wool1 fur1 and hair4 ,what cotton is as a vegetable product ,i shall not in detail describe1 but ,i will refer you to the interesting and complete work of ,dr4 ,bowman1 ,on the ,structure of the ,cotton ,fibre4 ,suffice it to say that in certain plants and trees the seeds or fruit are surrounded1 in the pods in which they develop1 with a downy substance1 and that the cotton shrub belongs to this class of plants4 ,a fibre picked out from the mass of the downy substance referred to1 and examined under the microscope1 is found to be a spirally twisted band2 or better1 an irregular1 more or less flattened and twisted tube 7see ,fig4 #a74 ,we know it is a tube1 because on taking a thin1 narrow slice across a fibre and examining the slice under the microscope1 we can see the hole or perforation up the centre1 forming the axis of the tube 7see ,fig4 #b74 ,mr4 ,h4 de ,mosenthal1 in an extremely interesting and valuable paper 7see ,j4,s4,c4,i41#a #aijd1 vol4 xxiii4 p4 #bib71 has recently shown that the cuticle of the cotton fibre is extremely porous1 having1 in addition to pores1 what appear to be minute stomata1 the latter being frequently arranged in oblique rows1 as if they led into oblique lateral channels4 ,a cotton fibre varies from #be to #f centimetres in length1 and in breadth from #jjag to #jje millimetre4 ,the characteristics mentioned make it very easy to distinguish cotton from other vegetable or animal fibres4 ,for example1 another vegetable fibre is flax1 or linen1 and this has a very different appearance under the microscope 7see ,fig4 #c74 ,it has a bamboo-like1 or jointed appearance2 its tubes are not flattened1 nor are they twisted4 ,flax belongs to a class called the bast fibres1 a name given to certain fibres obtained from the inner bark of different plants4 ,jute also is a bast fibre4 ,the finer qualities of it look like flax1 but1 as we shall see1 it is not chemically identical with cotton1 as linen or flax is4 ,another vegetable fibre1 termed cotton-silk1 from its beautiful1 lustrous1 silky appearance1 has excited some attention1 because it grows freely in the ,german colony called the ,camaroons1 and also on the ,gold ,coast4 ,this fibre1 under the microscope1 differs entirely in appearance from both cotton and flax fibres4 ,its fibres resemble straight and thin1 smooth1 transparent1 almost glassy tubes1 with large axial bores2 in fact1 if wetted in water you can see the water and air bubbles in the tubes under the microscope4 ,a more detailed account of cotton-silk appears in a paper read by me before the ,society of ,chemical ,industry in #ahhf 7see ,j4,s4,c4,i41 #ahhf1 vol4 v4 p4 #fdb74 ,now the substance of the cotton1 linen or flax1 as well as that of the cotton-silk fibres1 is termed1 chemically1 cellulose4 ,raw cotton consists of cellulose with about #e per cent4 of impurities4 ,this cellulose is a chemical compound of carbon1 hydrogen1 and oxygen1 and1 according to the relative proportions of these constituents1 it has had the chemical formula ,c#f;,h#aj,o#e assigned to it4 ,each letter stands for an atom of each constituent named1 and the numerals tell us the number of the constituent atoms in the whole compound atom of cellulose4 ,this cellulose is closely allied in composition to starch1 dextrin1 and a form of sugar called glucose4 ,it is possible to convert cotton rags into this form of sugar--glucose--by treating first with strong vitriol or sulphuric acid1 and then boiling with dilute acid for a long time4 ,before we leave these vegetable or cellulose fibres1 ,i will give you a means of testing them1 so as to enable you to distinguish them broadly from the animal fibres1 amongst which are silk1 wool1 fur1 and hair4 ,a good general test to distinguish a vegetable and an animal fibre is the following1 which is known as ,molisch's test3 ,to a very small quantity1 about #jja gram1 of the well-washed cotton fibre1 #a c4c4 of water is added1 then two to three drops of a #ae to #bj per cent4 solution of alpha-naphthol in alcohol1 and finally an excess of concentrated sulphuric acid2 on agitating1 a deep violet colour is developed4 ,by using thymol in place of the alpha-naphthol1 a red or scarlet colour is produced4 ,if the fibre were one of an animal nature1 merely a yellow or greenish-yellow coloured solution would result4 ,i told you1 however1 that jute is not chemically identical with cotton and linen4 ,the substance of its fibre has been termed bastose by ,cross and ,bevan1 who have investigated it4 ,it is not identical with ordinary cellulose1 for if we take a little of the jute1 soak it in dilute acid1 then in chloride of lime or hypochlorite of soda1 and finally pass it through a bath of sulphite of soda1 a beautiful crimson colour develops upon it1 not developed in the case of cellulose 7cotton1 linen1 etc474 ,it is certain that it is a kind of cellulose1 but still not identical with true cellulose4 ,all animal fibres1 when burnt1 emit a peculiar empyreumatic odour resembling that from burnt feathers1 an odour which no vegetable fibre under like circumstances emits4 ,hence a good test is to burn a piece of the fibre in a lamp flame1 and notice the odour4 ,all vegetable fibres are easily tendered1 or rendered rotten1 by the action of even dilute mineral acids2 with the additional action of steam1 the effect is much more rapid1 as also if the fibre is allowed to dry with the acid upon or in it4 ,animal fibres are not nearly so sensitive under these conditions4 ,but whereas caustic alkalis have not much effect on vegetable fibres1 if kept out of contact with the air1 the animal fibres are very quickly attacked4 ,superheated steam alone has but little effect on cotton or vegetable fibres1 but it would fuse or melt wool4 ,based on these differences1 methods have been devised and patented for treating mixed woollen and cotton tissues--7#a7 with hydrochloric acid gas1 or moistening with dilute hydrochloric acid and steaming1 to remove all the cotton fibre2 or 7#b7 with a jet of superheated steam1 under a pressure of #e atmospheres 7#ge lb4 per square inch71 when the woollen fibre is simply melted out of the tissue1 and sinks to the bottom of the vessel1 a vegetable tissue remaining 7,heddebault74 ,if we write on paper with dilute sulphuric acid1 and dry and then heat the place written upon1 the cellulose is destroyed and charred1 and we get black writing produced4 ,the principle involved is the same as in the separation of cotton from mixed woollen and cotton goods by means of sulphuric acid or vitriol4 ,the fabric containing cotton1 or let us say cellulose particles1 is treated with dilute vitriol1 pressed or squeezed1 and then roughly dried4 ,that cellulose then becomes mere dust1 and is simply beaten out of the intact woollen texture4 ,the cellulose is1 in a pure state1 a white powder1 of specific gravity #ae1 i4e4 one and a half times as heavy as water1 and is quite insoluble in such solvents as water1 alcohol1 ether2 but it does dissolve in a solution of hydrated oxide of copper in ammonia4 ,on adding acids to the cupric-ammonium solution1 the cellulose is reprecipitated in the form of a gelatinous mass4 ,cotton and linen are scarcely dissolved at all by a solution of basic zinc chloride4 ,footnote #a3 ,j4,s4,c4,i4 ,journal of the ,society of ,chemical ,industry4 ,illustration3 ,,fig4 #a4 ,illustration3 ,,fig4 #b4 ,illustration3 ,,fig4 #c4 ,illustration3 ,,fig4 #d4 ,silk4--,we now pass on to the animal fibres1 and of these we must first consider silk4 ,this is one of the most perfect substances for use in the textile arts4 ,a silk fibre may be considered as a kind of rod of solidified flexible gum1 secreted in and exuded from glands placed on the side of the body of the silk-worm4 ,in ,fig4 #d are shown the forms of the silk fibre1 in which there are no central cavities or axial bores as in cotton and flax1 and no signs of any cellular structure or external markings1 but a comparatively smooth1 glassy surface4 ,there is1 however1 a longitudinal groove of more or less depth4 ,the fibre is semi-transparent1 the beautiful pearly lustre being due to the smoothness of the outer layer and its reflection of the light4 ,in the silk fibre there are two distinct parts3 first1 the central portion1 or1 as we may regard it1 the true fibre1 chemically termed fibron2 and secondly1 an envelope composed of a substance or substances1 chemically termed sericin1 and often silk-glue or silk-gum4 ,both the latter and fibron are composed of carbon1 hydrogen1 nitrogen1 and oxygen4 ,here there is thus one element more than in the vegetable fibres previously referred to1 namely1 nitrogen2 and this nitrogen is contained in all the animal fibres4 ,the outer envelope of silk-glue or sericin can be dissolved off the inner fibron fibre by means of hot water1 or warm water with a little soap4 ,warm dilute 7that is1 weak7 acids1 such as sulphuric acid1 etc41 also dissolve this silk-glue1 and can be used like soap solutions for ungumming silk4 ,dilute nitric acid only slightly attacks silk1 and colours it yellow2 it would not so colour vegetable fibres1 and this forms a good test to distinguish silk from a vegetable fibre4 ,cold strong acetic acid1 so-called glacial acetic acid1 removes the yellowish colouring matter from raw silk without dissolving the sericin or silk-gum4 ,by heating under pressure with acetic acid1 however1 silk is completely dissolved4 ,silk is also dissolved by strong sulphuric acid1 forming a brown thick liquid4 ,if we add water to this thick liquid1 a clear solution is obtained1 and then on adding tannic acid the fibron is precipitated4 ,strong caustic potash or soda dissolves silk2 more easily if warm4 ,dilute caustic alkalis1 if sufficiently dilute1 will dissolve off the sericin and leave the inner fibre of fibron2 but they are not so good for ungumming silk as soap solutions are1 as the fibre after treatment with them is deficient in whiteness and brilliancy4 ,silk dissolves completely in hot basic zinc chloride solution1 and also in an alkaline solution of copper and glycerin1 which solutions do not dissolve vegetable fibres or wool4 ,chlorine and bleaching-powder solutions soon attack and destroy silk1 and so another and milder agent1 namely1 sulphurous acid1 is used to bleach this fibre4 ,silk is easily dyed by the aniline and coal-tar colours1 and with beautiful effect1 but it has little attraction for the mineral colours4 ,wool4--,next to silk as an animal fibre we come to wool and different varieties of fur and hair covering certain classes of animals1 such as sheep1 goats1 rabbits1 and hares4 ,generally1 and without going at all deeply into the subject1 we may say that wool differs from fur and hair1 of which we may regard it as a variety1 by being usually more elastic1 flexible1 and curly1 and because it possesses certain features of surface structure which confer upon it the property of being more easily matted together than fur and hair are4 ,we must first shortly consider the manner of growth of hair without spending too much time on this part of the subject4 ,the accompanying figure 7see ,fig4 #e7 shows a section of the skin with a hair or wool fibre rooted in it4 ,here we may see that the ground work1 if we may so term it1 is four-fold in structure4 ,proceeding downwards1 we have--7first7 the outer skin1 scarf-skin or cuticle2 7second7 a second layer or skin called the rete mucosum1 forming the epidermis2 7third7 papillary layer2 7fourth7 the corium layer1 forming the dermis4 ,the peculiar1 globular1 cellular masses below in the corium are called adipose cells1 and these throw off perspiration or moisture1 which is carried away to the surface by the glands shown 7called sudoriparous glands71 which1 as is seen1 pass independently off to the surface4 ,other glands terminate under the skin in the hair follicles1 which follicles or hair sockets contain or enclose the hair roots4 ,these glands terminating in the hair follicles secrete an oily substance1 which bathes and lubricates as well as nourishes the hair4 ,with respect to the origin of the hair or wool fibre1 this is formed inside the follicle by the exuding therefrom of a plastic liquid or lymph2 this latter gradually becomes granular1 and is then formed into cells1 which1 as the growth proceeds1 are elongated into fibres1 which form the central portion of the hair4 ,just as with the trunk of a tree1 we have an outer dense portion1 the bark1 an inner less dense and more cellular layer1 and an inmost portion which is most cellular and porous2 so with a hair1 the central portion is loose and porous1 the outer more and more dense4 ,on glancing at the figure 7,fig4 #f7 of the longitudinal section of a human hair1 we see first the outer portion1 like the bark of a tree1 consisting of a dense sheath of flattened scales1 then comes an inner lining of closely-packed fibrous cells1 and frequently an inner well-marked central bundle of larger and rounder cells1 forming a medullary axis4 ,the transverse section 7,fig4 #g7 shows this exceedingly well4 ,the end of a hair is generally pointed1 sometimes filamentous4 ,the lower extremity is larger than the shaft1 and terminates in a conical bulb1 or mass of cells1 which forms the root of the hair4 ,in the next figure 7,fig4 #h7 we are supposed to have separated these cells1 and above1 7a71 we see some of the cells from the central pith or medulla1 and fat globules2 between1 7b71 some of the intermediate elongated or angular cells2 and below1 7c71 two flattened1 compressed1 structureless1 and horny scales from the outer portion of the hair4 ,now these latter flattened scales are of great importance4 ,their character and mode of connection with the stratum1 or cortical substance1 below1 not only make all the difference between wool and hair1 but also determine the extent and degree of that peculiar property of interlocking of the hairs known as felting4 ,let us now again look at a human hair4 ,the light was reflected from this hair as it lay under the microscope1 and now we see the reason of the saw-like edge in the longitudinal section1 for just as the tiles lie on the roof of a house1 or the scales on the back of a fish1 so the whole surface of the hair is externally coated with a firmly adhering layer of flat overlying scales1 with not very even upper edges1 as you see4 ,the upper or free edges of these scales are all directed towards the end of the hair1 and away from the root4 ,but when you look at a hair in its natural state you cannot see these scales1 so flat do they lie on the hair-shaft4 ,what you see are only irregular transverse lines across it4 ,now ,i come to a matter of great importance1 as will later on appear in connection with means for promoting felting properties4 ,if a hair such as described1 with the scales lying flat on the shaft1 be treated with certain substances or reagents which act upon and dissolve1 or decompose or disintegrate its parts1 then the free edges of these scales rise up1 they set their backs up1 so to say4 ,they1 in fact1 stand off like the scales of a fir-cone1 and at length act like the fir-cone in ripening1 at last becoming entirely loose4 ,as regards wool and fur1 these scales are of the utmost importance1 for very marked differences exist even in the wool of a single sheep1 or the fur of a single hare4 ,it is the duty of the wool-sorter to distinguish and separate the various qualities in each fleece1 and of the furrier to do the same in the case of each fur4 ,in short1 upon the nature and arrangement and conformation of the scales on the hair-shafts1 especially as regards those free upper edges1 depends the distinction of the value of many classes of wool and fur4 ,these scales vary both as to nature and arrangement in the case of the hairs of different animals1 so that by the aid of the microscope we have often a means of determining from what kind of animal the hair has been derived4 ,it is on the nature of this outside scaly covering of the shaft1 and in the manner of attachment of these scaly plates1 that the true distinction between wool and hair rests4 ,the principal epidermal characteristic of a true wool is the capacity of its fibres to felt or mat together4 ,this arises from the greater looseness of the scaly covering of the hair1 so that when opposing hairs come into contact1 the scales interlock 7see ,fig4 #i71 and thus the fibres are held together4 ,just as with hair1 the scales of which have their free edges pointing upwards away from the root1 and towards the extremity of the hair1 so with wool4 ,when the wool is on the back of the sheep1 the scales of the woolly hair all point in the same direction1 so that while maintained in that attitude the individual hairs slide over one another1 and do not tend to felt or mat2 if they did1 woe betide the animal4 ,the fact of the peculiar serrated1 scaly structure of hair and wool is easily proved by working a hair between the fingers4 ,if1 for instance1 a human hair be placed between finger and thumb1 and gently rubbed by the alternate motion of finger and thumb together1 it will then invariably move in the direction of the root1 quite independently of the will of the person performing the test4 ,a glance at the form of the typical wool fibres shown 7see ,fig4 #aj71 will show the considerable difference between a wool and a hair fibre4 ,you will observe that the scales of the wool fibre are rather pointed than rounded at their free edges1 and that at intervals we have a kind of composite and jagged-edged funnels1 fitting into each other1 and thus making up the covering of the cylindrical portion of the fibre4 ,the sharpened1 jagged edges enable these scales more easily to get under the opposing scales1 and to penetrate inwards and downwards according to the pressure exerted4 ,the free edges of the scales of wool are much longer and deeper than in the case of hair4 ,in hair the overlapping scales are attached to the under layer up to the edges of those scales1 and at this extremity can only be detached by the use of certain reagents4 ,but this is not so with wool1 for here the ends of the scales are1 for nearly two-thirds of their length1 free1 and are1 moreover1 partially turned outwards4 ,one of the fibres shown in ,fig4 #aj is that of the merino sheep1 and is one of the most valuable and beautiful wools grown4 ,there you have the type of a fibre best suited for textile purposes1 and the more closely different hairs approach this1 the more suitable and valuable they become for those purposes1 and vice vers4 ,with regard to the curly structure of wool1 which increases the matting tendency1 though the true cause of this curl is not known1 there appears to be a close relationship between the tendency to curl1 the fineness of the fibre1 and the number of scales per linear inch upon the surface4 ,with regard to hair and fur1 ,i have already shown that serrated fibres are not specially peculiar to sheep1 but are much more widely diffused4 ,most of the higher members of the mammalia family possess a hairy covering of some sort1 and in by far the larger number is found a tendency to produce an undergrowth of fine woolly fibre1 especially in the winter time4 ,the differences of human hair and hairs generally1 from the higher to the lower forms of mammalia1 consist only in variations of size and arrangement as regards the cells composing the different parts of the fibre1 as well as in a greater or less development of the scales on the covering or external hair surface4 ,thus1 under the microscope1 the wool and hairs of various animals1 as also even hairs from different parts of the same animal1 show a great variety of structure1 development1 and appearance4 ,illustration3 ,,fig4 #e4 ,illustration3 ,,fig4 #f4 ,illustration3 ,,fig4 #g4 ,illustration3 ,,fig4 #h4 ,illustration3 ,,fig4 #i4 ,illustration3 ,finest merino wool fibre4 ,typical wool fibre4 ,fibre of wool from ,chinese sheep4 ,,fig4 #aj4 ,illustration3 ,,fig4 #aa4 ,illustration3 ,,fig4 #ab4 ,we have already observed that hair1 if needed for felting1 is all the better--provided1 of course1 no injury is done to the fibre itself--for some treatment1 by which the scales otherwise lying flatter on the hair-shafts than in the case of the hairs of wool1 are made to stand up somewhat1 extending outwards their free edges4 ,this brings me to the consideration of a practice pursued by furriers for this purpose1 and known as the scretage or carrotting process2 it consists in a treatment with a solution of mercuric nitrate in nitric acid1 in order to improve the felting qualities of the fur4 ,this acid mixture is brushed on to the fur1 which is cut from the skin by a suitable sharp cutting or shearing machine4 ,a ,manchester furrier1 who gave me specimens of some fur untreated by the process1 and also some of the same fur that had been treated1 informed me that others of his line of business use more mercury than he does1 i4e4 leave less free nitric acid in their mixture2 but he prefers his own method1 and thinks it answers best for the promotion of felting4 ,the treated fur he gave me was turned yellow with the nitric acid1 in parts brown1 and here and there the hairs were slightly matted with the acid4 ,in my opinion the fur must suffer from such unequal treatment with such strong acid1 and in the final process of finishing ,i should not be surprised if difficulty were found in getting a high degree of lustre and finish upon hairs thus roughened or partially disintegrated4 ,figs4 #aa and #ab respectively illustrate fur fibres from different parts of the same hare before and after the treatment4 ,in examining one of these fibres from the side of a hare1 you see what the cause of this roughness is1 and what is also the cause of the difficulty in giving a polish or finish4 ,the free edges are partially disintegrated1 etched as it were1 besides being caused to stand out4 ,a weaker acid ought to be used1 or more mercury and less acid4 ,as we shall afterwards see1 another dangerous agent1 if not carefully used1 is bichrome 7bichromate of potassium71 which is also liable to roughen and injure the fibre1 and thus interfere with the final production of a good finish4 ,,lecture ,,ii ,,textile ,,fibres1 ,,principally ,,wool1 ,,fur1 ,,and ,,hair--,continued ,with regard to the preparation of fur by acid mixtures for felting1 mentioned in the last lecture1 ,i will tell you what ,i think ,i should recommend4 ,in all wool and fur there is a certain amount of grease1 and this may vary in different parts of the material4 ,where there is most1 however1 the acid1 nitric acid1 or nitric acid solution of nitrate of mercury1 will wet1 and so act on the fur1 least4 ,but the action ought to be uniform1 and ,i feel sure it cannot be until the grease is removed4 ,i should therefore first wash the felts on the fur side with a weak alkaline solution1 one of carbonate of soda1 free from any caustic1 to remove all grease1 then with water to remove alkali2 and my belief is that a weaker and less acid solution of nitric acid and nitrate of mercury1 and a smaller quantity of it1 would then do the work required1 and do it more uniformly4 ,a question frequently asked is3 ,why will dead wool not felt8 ,answer3 ,if the animal become weak and diseased1 the wool suffers degradation2 also1 with improvement in health follows pari passu1 improvement in the wool structure1 which means increase both in number and vigour of the scales on the wool fibres1 increase of the serrated ends of these1 and of their regularity4 ,in weakness and disease the number of scales in a given hair-shaft diminishes1 and these become finer and less pronounced4 ,the fibres themselves also become attenuated4 ,hence when disease becomes death1 we have considerably degraded fibres4 ,this is seen clearly in the subjoined figures 7see ,fig4 #ac71 which are of wool fibres from animals that have died of disease4 ,the fibres are attenuated and irregular1 the scale markings and edges have almost disappeared in some places1 and are generally scanty and meagre in development4 ,it is no wonder that such dead wool will be badly adapted for felting4 ,dead wool is nearly as bad as kempy wool1 in which malformation of fibre has occurred4 ,in such kemps1 as ,dr4 ,bowman has shown1 scales have disappeared1 and the fibre has become1 in part or whole1 a dense1 non-cellular structure1 resisting dye-penetration and felting 7see ,fig4 #ad74 ,illustration3 ,,fig4 #ac4 ,illustration3 ,,fig4 #ad4 ,one of the physical properties of wool is its hygroscopicity or power of absorbing moisture4 ,as the very structure of wool and fur fibre would lead us to suppose1 these substances are able to absorb a very considerable amount of water without appearing damp4 ,if exposed freely to the air in warm and dry weather1 wool retains from #h to #aj per cent41 and if in a damp place for some time1 it may absorb as much as from #cj to #ej per cent4 of water3 ,wool1 fur1 or hair that has been washed1 absorbs the most moisture2 indeed1 the amount of water taken up varies inversely with the fatty or oily matter present4 ,hence the less fat the more moisture4 ,in the washed wool1 those fibres in which the cells are more loosely arranged have the greatest absorbing power for water4 ,no doubt the moisture finds its way in between the cells of the wool fibre from which the oil or fat has been removed4 ,but ,i need hardly remind you that if wool and fur are capable1 according to the circumstances under which they are placed1 of absorbing so much moisture as that indicated1 it becomes 7especially in times of pressure and competition7 very important to inquire if it be not worth while to cease paying wool and fur prices for mere water4 ,this question was answered long ago in the negative by our ,continental neighbours1 and in ,germany1 ,france1 and ,switzerland official conditioning establishments have been founded by the ,governments of those countries for the purpose of testing lots of purchased wool and silk1 etc41 for moisture1 in order that this moisture may be deducted from the invoices1 and cash paid for real dry wool1 etc4 ,i would point out that if you1 as hat manufacturers1 desire to enter the lists with ,germany1 you must not let her have any advantage you have not1 and it is an advantage to pay for what you know exactly the composition of1 rather than for an article that may contain #g per cent4 or1 for aught you know1 #ag per cent4 or #cj per cent4 of water4 ,there is1 so far as ,i know1 no testing for water in wools and furs in this country1 and certainly no conditioning establishments 7#ahhg71 and1 ,i suppose1 if a ,german or ,french wool merchant or furrier could be imagined as selling wool1 etc41 in part to a ,german or ,french firm1 and in part to an ,english one1 the latter would take the material without a murmur1 though it might contain #aj per cent41 or1 peradventure1 #cj per cent4 of water1 and no doubt the foreign1 just as the ,english merchant or dealer1 would get the best price he could1 and regard the possible #aj per cent4 or #cj per cent4 of water present with certainly the more equanimity the more of that very cheap element there were present4 ,but look at the other side4 ,the ,german or ,french firm samples its lot as delivered1 takes the sample to be tested1 and that #aj or #cj per cent4 of water is deducted1 and only the dry wool is paid for4 ,a few little mistakes of this kind1 ,i need hardly say1 will altogether form a kind of vade mecum for the foreign competitor4 ,we will now see what the effect of water is in the felting operation4 ,especially hot water assists that operation1 and the effect is a curious one4 ,when acid is added as well1 the felting is still further increased1 and shrinking also takes place4 ,as already shown you1 the free ends of the scales1 themselves softened by the warm dilute acid1 are extended and project more1 and stand out from the shafts of the hairs4 ,on the whole1 were ,i a hat manufacturer1 ,i should prefer to buy my fur untreated by that nitric acid and mercury process previously referred to1 and promote its felting properties myself by the less severe and more rational course of proceeding1 such1 for example1 as treatment with warm dilute acid4 ,we have referred to two enemies standing in the way to the obtainment of a final lustre and finish on felted wool or fur1 now let us expose a third4 ,in the black dyeing of the hat-forms a boiling process is used4 ,let us hear what ,dr4 ,bowman1 in his work on the wool fibre1 says with regard to boiling with water4 ,wool which looked quite bright when well washed with tepid water1 was decidedly duller when kept for some time in water at a temperature of #afj ,f41 and the same wool1 when subjected to boiling water at #bab ,f41 became quite dull and lustreless4 ,when tested for strength1 the same fibres which carried on the average #ejj grains without breaking before boiling1 after boiling would not bear more than #dhj grains4 ,hence this third enemy is a boiling process1 especially a long-continued one if only with water itself4 ,if we could use coal-tar colours and dye in only a warm weak acid bath1 not boil1 we could get better lustre and finish4 ,we will now turn our attention to the chemical composition of wool and fur fibres4 ,on chemical analysis still another element is found over and above those mentioned as the constituents of silk fibre4 ,in silk1 you will recollect1 we observed the presence of carbon1 hydrogen1 oxygen1 and nitrogen4 ,in wool1 fur1 etc41 we must add a fifth constituent1 namely1 sulphur4 ,here is an analysis of pure ,german wool--,carbon1 #dibe per cent42 hydrogen1 #geg2 oxygen1 #bcff2 nitrogen1 #aehf2 sulphur1 #cff--total1 #ajjjj4 ,if you heat either wool1 fur1 or hair to #acj ,c41 it begins to decompose1 and to give off ammonia2 if still further heated to from #adj to #aej ,c41 vapours containing sulphur are evolved4 ,if some wool be placed in a dry glass tube1 and heated strongly so as to cause destructive distillation1 products containing much carbonate of ammonium are given off4 ,the ammonia is easily detected by its smell of hartshorn and the blue colour produced on a piece of reddened litmus paper1 the latter being a general test to distinguish alkalis1 like ammonia1 soda1 and potash1 from acids4 ,no vegetable fibres will1 under any circumstances1 give off ammonia4 ,it may be asked1 ,but what does the production of ammonia prove8 ,i reply1 the backbone1 chemically speaking1 of ammonia is nitrogen4 ,ammonia is a compound of nitrogen and hydrogen1 and is formulated ,,nh#c1 and hence to discover ammonia in the products as mentioned is to prove the prior existence of its nitrogen in the wool1 fur1 and hair fibres4 ,action of ,acids on ,wool1 etc4--,dilute solutions of vitriol 7sulphuric acid7 or hydrochloric acid 7muriatic acid1 spirits of salt7 have little effect on wool1 whether warm or cold1 except to open out the scales and confer roughness on the fibre4 ,used in the concentrated state1 however1 the wool or fur would soon be disintegrated and ruined4 ,but under all circumstances the action is far less than on cotton1 which is destroyed at once and completely4 ,nitric acid acts like sulphuric and hydrochloric acids1 but it gives a yellow colour to the fibre4 ,you see this clearly enough in the fur that comes from your furriers after the treatment they subject it to with nitric acid and nitrate of mercury4 ,there is a process known called the stripping of wool1 and it consists in destroying the colour of wool and woollen goods already dyed1 in order that they may be re-dyed4 ,listen1 however1 to the important precautions followed3 ,a nitric acid not stronger than from #c to #d ,twaddell is used1 and care is taken not to prolong the action more than three or four minutes4 ,action of ,alkalis4--,alkalis have a very considerable action on fur and wool1 but the effects vary a good deal according to the kind of alkali used1 the strength and the temperature of the solution1 as also1 of course1 the length of period of contact4 ,the caustic alkalis1 potash and soda1 under all conditions affect wool and fur injuriously4 ,in fact1 we have a method of recovering indigo from indigo-dyed woollen rags1 based on the solubility of the wool in hot caustic soda4 ,the wool dissolves1 and the indigo1 being insoluble1 remains1 and can be recovered4 ,alkaline carbonates and soap in solution have little or no injurious action if not too strong1 and if the temperature be not over #ej ,c4 7#ajf ,f474 ,soap and carbonate of ammonium have the least injurious action4 ,every washer or scourer of wool1 when he uses soaps1 should first ascertain if they are free from excess of alkali1 i4e4 that they contain no free alkali2 and when he uses soda ash 7sodium carbonate71 that it contains no caustic alkali4 ,lime1 in water or otherwise1 acts injuriously1 rendering the fibre brittle4 ,reactions and tests proving chemical differences and illustrating modes of discriminating and separating vegetable fibres1 silk and wool1 fur1 etc4--,you will remember ,i stated that the vegetable fibre differs chemically from those of silk1 and silk from wool1 fur1 and hair1 in that with the first we have as constituents only carbon1 hydrogen1 and oxygen2 in silk we have carbon1 hydrogen1 oxygen1 and nitrogen2 whilst in wool1 fur1 and hair we have carbon1 hydrogen1 oxygen1 nitrogen1 and sulphur4 ,i have already shown you that if we can liberate by any means ammonia from a substance1 we have practically proved the presence of nitrogen in that substance1 for ammonia is a nitrogen compound4 ,as regards sulphur and its compounds1 that ill-smelling gas1 sulphuretted hydrogen1 which occurs in rotten eggs1 in organic effluvia from cesspools and the like1 and which in the case of bad eggs1 and to some extent with good eggs1 turns the silver spoons black1 and in the case of white lead paints turns these brown or black1 ,i can show you some still more convincing proofs that sulphur is contained in wool1 fur1 and hair1 and not in silk nor in vegetable fibres4 ,first1 ,i will heat strongly some cotton with a little soda-lime in a tube1 and hold a piece of moistened red litmus paper over the mouth of the tube4 ,if nitrogen is present it will take up hydrogen in the decomposition ensuing1 and escape as ammonia1 which will turn the red litmus paper blue4 ,with the cotton1 however1 no ammonia escapes1 no turning of the piece of red litmus paper blue is observed1 and so no nitrogen can be present in the cotton fibre4 ,secondly1 ,i will similarly treat some silk4 ,ammonia escapes1 turns the red litmus paper blue1 possesses the smell like hartshorn1 and produces1 with hydrochloric acid on the stopper of a bottle1 dense white fumes of sal-ammoniac 7ammonium chloride74 ,hence silk contains nitrogen4 ,thirdly1 ,i will heat some fur with soda-lime4 ,ammonia escapes1 giving all the reactions described under silk4 ,hence fur1 wool1 etc41 contain nitrogen4 ,as regards proofs of all three of these classes of fibres containing carbon1 hydrogen1 and oxygen1 the char they all leave behind on heating in a closed vessel is the carbon itself present4 ,for the hydrogen and oxygen1 a perfectly dry sample of any of these fabrics is taken1 of course in quantity1 and heated strongly in a closed vessel furnished with a condensing worm like a still4 ,you will find all give you water as a condensate--the vegetable fibre1 acid water2 the animal fibres1 alkaline water from the ammonia4 ,the presence of water proves both hydrogen and oxygen1 since water is a compound of these elements4 ,if you put a piece of potassium in contact with the water1 the latter will at once decompose1 the potassium absorbing the oxygen1 and setting free the hydrogen as gas1 which you could collect and ignite with a match1 when you would find it would burn4 ,that hydrogen was the hydrogen forming part of your cotton1 silk1 or wool1 as the case might be4 ,we must now attack the question of sulphur4 ,first1 we prepare a little alkaline lead solution 7sodium plumbate7 by adding caustic soda to a solution of lead acetate or sugar of lead1 until the white precipitate first formed is just dissolved4 ,that is one of our reagents2 the other is a solution of a red-coloured salt called nitroprusside of sodium1 made by the action of nitric acid on sodium ferrocyanide 7yellow prussiate74 ,the first-named is very sensitive to sulphur1 and turns black directly4 ,to show this1 we take a quantity of flowers of sulphur1 dissolve in caustic soda1 and add to the lead solution4 ,it turns black at once1 because the sulphur unites with the lead to form black sulphide of lead4 ,the nitroprusside1 however1 gives a beautiful crimson-purple coloration4 ,now on taking a little cotton and heating with the caustic alkaline lead solution1 if sulphur were present in that cotton1 the fibre would turn black or brown1 for the lead would at once absorb such sulphur1 and form in the fibre soaked with it1 black sulphide of lead4 ,no such coloration is formed1 so cotton does not contain sulphur4 ,secondly1 we must test silk4 ,silk contains nitrogen1 like wool1 but does it contain sulphur8 ,the answer furnished by our tests is--no6 since the fibre is not coloured brown or black on heating with the alkaline lead solution4 ,thirdly1 we try some white ,berlin wool1 so that we can easily see the change of colour if it takes place4 ,in the hot lead solution the wool turns black1 lead sulphide being formed4 ,on adding the nitroprusside solution to a fresh portion of wool boiled with caustic soda1 to dissolve out the sulphur1 a splendid purple coloration is produced4 ,fur and hair would1 of course1 do the same thing4 ,lead solutions have been used for dyeing the hair black2 not caustic alkaline solutions like this1 however4 ,they would do something more than turn the hair black--probably give rise to some vigorous exercise of muscular power6 ,still it has been found that even the lead solutions employed have1 through gradual absorption into the system1 whilst dyeing the hair black1 also caused colics and contractions of the limbs4 ,having now found means for proving the presence of the various elements composing cotton1 silk1 and wool1 fur or hair1 we come to methods that have been proposed for distinguishing these fibres more generally1 and for quantitatively determining them in mixtures4 ,one of the best of the reagents for this purpose is the basic zinc chloride already referred to4 ,this is made as follows3 #ajj parts of fused zinc chloride1 #he parts of water1 and #d parts of zinc oxide are boiled together until a clear solution is obtained4 ,this solution dissolves silk slowly in the cold1 quickly if hot1 and forms a thick gummy liquid4 ,wool1 fur1 and vegetable fibres are not affected by it4 ,hence if we had a mixture1 and treated with this solution1 we could strain off the liquid containing the dissolved silk1 and would get cotton and wool left4 ,on weighing before and after such treatment1 the difference in weights would give us the silk present4 ,the residue boiled with caustic soda would lose all its wool1 which is soluble in hot strong caustic alkali4 ,again straining off1 we should get only the cotton or other vegetable fibre left1 and thus our problem would be solved4 ,of course there are certain additional niceties and modifications still needed1 and ,i must refer you for the method in full to the ,journal of the ,society of ,chemical ,industry1 #ahhb1 page #fd2 also #ahhd1 page #eag4 ,i will now conclude with some tests with alkaline and acid reagents1 taken in order1 and first the acids4 ,these will also impress upon our minds the effects of acids and alkalis on the different kinds of fibres4 ,i4 ,in three flasks three similar portions of cotton lamp-wick1 woollen yarn1 and silk are placed1 after previously moistening them in water and wringing them out4 ,to each is now added similar quantities of concentrated sulphuric acid4 ,the cotton is quickly broken up and dissolved1 especially if assisted by gentle warming1 and at last a brown1 probably a black-brown1 solution is obtained4 ,the woollen is a little broken up1 but not much to the naked eye1 and the vitriol is not coloured4 ,the silk is at once dissolved1 even in the cold acid4 ,we now add excess of water to the contents of each flask4 ,a brownish1 though clear1 solution is produced in the case of cotton2 the woollen floats not much injured in the acid1 whilst a clear limpid solution is obtained with the silk4 ,on adding tannic acid solution to all three1 only the silk yields a precipitate1 a rather curdy one consisting of fibron4 ,,ii4 ,three specimens of cotton1 wool1 and silk1 respectively1 are touched with nitric acid4 ,cotton is not coloured1 but wool and silk are stained yellow2 they are practically dyed4 ,,iii4 ,three specimens1 of cotton1 wool1 and silk1 respectively1 are placed in three flasks1 and caustic soda solution of specific gravity #aje 7#aj ,twaddell7 is added4 ,on boiling1 the wool and silk dissolve1 whilst the cellulose fibre1 cotton1 remains undestroyed4 ,,iv4 ,if1 instead of caustic soda as in ,,iii41 a solution of oxide of copper in ammonia be used1 cotton and silk are dissolved1 but wool remains unchanged1 i4e4 undissolved4 ,if sugar or gum solutions be added to the solutions of cotton and silk1 the cotton cellulose is precipitated1 whilst the silk is not1 but remains in solution4 ,v4 ,another alkaline solvent for silk1 which1 however1 leaves undissolved cotton and wool1 is prepared as follows3 #af grains of copper sulphate 7blue vitriol1 bluestone7 are dissolved in #aej c4c4 of water1 and then #af grains of glycerin are added4 ,to this mixture a solution of caustic soda is added until the precipitate first formed is just re-dissolved1 so as not to leave an excess of caustic soda present4 ,,lecture ,,iii ,,water3 ,,its ,,chemistry ,,and ,,properties2 ,,impurities ,,and ,,their ,,action2 ,,tests ,,of ,,purity ,i have already had occasion to refer1 in my last ,lecture1 to water as a chemical substance1 as a compound containing and consisting of hydrogen and oxygen4 ,what are these water constituents1 hydrogen and oxygen8 ,each of them is a gas1 but each a gas having totally different properties4 ,on decomposing water and collecting the one of these two gases1 the hydrogen gas1 in one vessel1 and the other1 the oxygen gas1 in another vessel1 twice as large a volume of hydrogen gas is given off by the decomposing water as of oxygen4 ,you may now notice a certain meaning in the formula assigned to water1 ,h#b,o3 two volumes of hydrogen combined with one of oxygen2 and it may be added that when such combination takes place1 not three volumes of resulting water vapour 7steam71 but two volumes are produced4 ,this combination of the two gases1 when mixed together1 is determined by heating to a high temperature1 or by passing an electric spark2 it then takes place with the consequent sudden condensation of three volumes of mixture to two of compound1 so as to cause an explosion4 ,i may also mention that as regards the weights of these bodies1 oxygen and hydrogen1 the first is sixteen times as heavy as the second2 and since we adopt hydrogen as the unit1 we may consider ,h to stand for hydrogen1 and also to signify #a--the unit2 whilst ,o means oxygen1 and also #af4 ,hence the compound atom or molecule of water1 ,h#b,o1 weighs #ah4 ,i must now show you that these two gases are possessed of totally different properties4 ,some gases will extinguish a flame2 some will cause the flame to burn brilliantly1 but will not burn themselves2 and some will take fire and burn themselves1 though extinguishing the flame which has ignited them4 ,we say the first are non-combustible1 and will not support combustion2 the second are supporters of combustion1 the third are combustible gases4 ,of course these are1 as the lawyers say1 only ex parte statements of the truth2 still they are usually accepted4 ,oxygen gas will ignite a red-hot match1 but hydrogen will extinguish an inflamed one1 though it will itself burn4 ,you generally think of water as the great antithesis of1 the universal antidote for1 fire4 ,the truth is here again only of an ex parte character1 as ,i will show you4 ,if ,i can1 by means of a substance having a more intense affinity for oxygen than hydrogen has1 rob water of its oxygen1 ,i necessarily set the hydrogen that was combined with that oxygen free4 ,if the heat caused by the chemical struggle1 so to say1 is great1 that hydrogen will be inflamed and burn4 ,thus we are destroying that antithesis1 we are causing the water to yield us fire4 ,i will do this by putting potassium on water1 and even in the cold this potassium will seize upon the oxygen of the water1 and the hydrogen will take fire4 ,specific ,gravity4--,we must now hasten to other considerations of importance4 ,water is generally taken as the unit in specific gravities assigned to liquids and solids4 ,this simply means that when we desire to express how heavy a thing is1 we are compelled to say it is so many times heavier or lighter than something4 ,that something is generally water1 which is regarded1 consequently1 as unit or figure #a4 ,a body of specific gravity #ae1 or #a-a_/b1 means that that body is #a-a_/b or #ae times as heavy as water4 ,as hat manufacturers1 you will have mostly to do with the specific gravities of liquids1 aqueous solutions1 and you will hear more of ,twaddell degrees4 ,the ,twaddell hydrometer1 or instrument for measuring the specific gravities of liquids1 is so constructed that when it stands in water1 the water is just level with its zero or #j mark4 ,well1 since in your reading of methods and new processes1 you will often meet with specific gravity numbers and desire to convert these into ,twaddell degrees1 ,i will give you a simple means of doing this4 ,add cyphers so as to make into a number of four figures1 then strike out the unit and decimal point farthest to the left1 and divide the residue by #e1 and you get the corresponding ,twaddell degrees4 ,if you have ,twaddell degrees1 simply multiply by #e1 and add #ajjj to the result1 and you get the specific gravity as usually taken1 with water as the unit1 or in this case as #ajjj4 ,an instrument much used on the ,continent is the ,beaum hydrometer4 ,the degrees 7n7 indicated by this instrument can be converted into specific gravity 7d7 by the formula3 d #addc_/7addc - n7 ,ebullition or ,boiling of ,water1 ,steam4--,the atmosphere around us is composed of a mixture of nitrogen and oxygen gases2 not a compound of these gases1 as water is of hydrogen and oxygen1 but a mixture more like sand and water or smoke and air4 ,this mass of gases has weight1 and presses upon objects at the surface of the earth to the extent of #ae lb4 on the square inch4 ,now some liquids1 such as water1 were it not for this atmospheric pressure1 would not remain liquids at all1 but would become gases4 ,the pressure thus tends to squeeze gases together and convert them into liquids4 ,any force that causes gases to contract will do the same thing1 of course--for example1 cold2 and ceteris paribus removal of pressure and expansion by heat will act so as to gasify liquids4 ,when in the expansion of liquids a certain stage or degree is reached1 different for different liquids1 gas begins to escape so quickly from the liquid that bubbles of vapour are continually formed and escape4 ,this is called ebullition or boiling4 ,a certain removal of pressure1 or expansion by heat1 is necessary to produce this1 i4e4 to reach the boiling-point of the liquid4 ,as regards the heat necessary for the boiling of water at the surface of the earth1 i4e4 under the atmospheric pressure of #ae lb4 on the square inch1 this is shown on the thermometer of ,fahrenheit as #bab1 and on the simpler centigrade one1 as #ajj1 water freezing at #j ,c4 ,but if what ,i have said is true1 when we remove some of the atmospheric pressure1 the water should boil with a less heat than will cause the mercury in the thermometer to rise to #ajj ,c41 and if we take off all the pressure1 the water ought to boil and freeze at the same time4 ,this actually happens in the ,carr ice-making machine4 ,the question now arises1 ,why does the water freeze in the ,carr machine8 ,all substances require certain amounts of heat to enable them to take and to maintain the liquid state if they are ordinarily solid1 and the gaseous state if ordinarily liquid or solid1 and the greater the change of state the greater the heat needed4 ,moreover1 this heat does not make them warm1 it is simply absorbed or swallowed up1 and becomes latent1 and is merely necessary to maintain the new condition assumed4 ,in the case of the ,carr machine1 liquid water is1 by removal of the atmospheric pressure1 coerced1 as it were1 to take the gaseous form4 ,but to do so it needs to absorb the requisite amount of heat to aid it in taking that form1 and this heat it must take up from all surrounding warm objects4 ,it absorbs quickly all it can get out of itself as liquid water1 out of the glass vessel containing it1 and from the surrounding air4 ,but the process of gasification with ebullition goes on so quickly that the temperature of the water thus robbed of heat quickly falls to #j ,c41 and the remaining water freezes4 ,thus1 then1 by pumping out the air from a vessel1 i4e4 working in a vacuum1 we can boil a liquid in such exhausted vessel far below its ordinary boiling temperature in the open air4 ,this fact is of the utmost industrial importance4 ,but touching this question of latent heat1 you may ask me for my proof that there is latent heat1 and a large amount of it1 in a substance that feels perfectly cold4 ,i have told you that a gasified liquid1 or a liquefied solid1 or most of all a gasified solid1 contains such heat1 and if reconverted into liquid and solid forms respectively1 that heat is evolved1 or becomes sensible heat1 and then it can be decidedly felt and indicated by the thermometer4 ,take the case of a liquid suddenly solidifying4 ,the heat latent in that liquid1 and necessary to keep it a liquid1 is no longer necessary and comes out1 and the substance appears to become hot4 ,quicklime is a cold1 white1 solid substance1 but there is a compound of water and lime--slaked lime--which is also a solid powdery substance1 called by the chemist1 hydrate of lime4 ,the water used to slake the quicklime is a liquid1 and it may be ice-cold water1 but to form hydrate of lime it must assume a solid form1 and hence can and does dispense with its heat of liquefaction in the change of state4 ,you all know how hot lime becomes on slaking with water4 ,of course we have heat of chemical combination here as well as evolution of latent heat4 ,as another example1 we may take a solution of acetate of soda1 so strong that it is just on the point of crystallising4 ,if it crystallises it solidifies1 and the liquid consequently gives up its latent heat of liquefaction4 ,we will make it crystallise1 first connecting the tube containing it to another one containing a coloured liquid and closed by a cork carrying a narrow tube dipping into the coloured liquid4 ,on crystallising1 the solution gives off heat1 as is shown by the expansion of the air in the corked tube1 and the consequent forcing of the coloured liquid up the narrow tube4 ,consequently in your works you never dissolve a salt or crystal in water or other liquid without rendering heat latent1 or consuming heat2 you never allow steam to condense in the steam pipes about the premises without losing vastly more heat than possibly many are aware of4 ,let us inquire as to the latent heat of water and of steam4 ,latent ,heats of ,water and ,steam4--,if we mix #a kilogram 7about #b lb47 of ice 7of course at zero or #j ,c47 with #a kilogram of water at #gi ,c41 and stir well till the ice is melted1 i4e4 has changed its state from solid to liquid1 we find1 on putting a thermometer in1 the temperature is only #j ,c4 ,this simply means that #gi of heat 7centigrade degrees7 have become latent1 and represent the heat of liquefaction of #a kilogram of ice4 ,had we mixed #a kilogram of water at #j ,c4 with #a kilogram of water at #gi ,c4 there would have been no change of state1 and the temperature of the mixture might be represented as a distribution of the #gi ,c4 through the whole mass of the #b kilograms1 and so would be #ci-a_/b ,c4 ,we say1 therefore1 the latent heat of water is the heat which is absorbed or rendered latent when a unit of weight1 say #a kilogram of water as ice1 melts and liquefies to a unit of water at zero1 or it is #gi heat units4 ,these #gi units of heat would raise #gi units of weight of liquid water through #a ,c41 or one unit of liquid water through #gi4 ,let us now inquire what the latent heat of steam is4 ,if we take #a kilogram of water at #j ,c4 and blow steam from boiling water at #ajj ,c4 into it until the water just boils1 and then stop and weigh the resulting water1 we shall find it amounts to #aahg kilograms1 so that #jahg kilogram of water which was in the gaseous steam form1 and had besides a sensible heat of #ajj ,c41 has changed its state to that of liquid water4 ,this liquid water1 being at the boiling-point1 has still the #ajj ,c4 of sensible heat1 and hence the water in the gaseous steam form can have given up to the water at #j ,c4 into which it was blown1 only the latent heat of gasification which was not sensible1 but by virtue of which it was enabled to assume the gaseous form4 ,but if #jahg kilogram of steam at #ajj ,c4 can heat #a kilogram of water through #ajj degrees1 then #a kilogram of steam can raise #ecf kilograms of ice-cold water through #ajj degrees1 or #ecf kilograms through #a degree1 and thus the latent heat of steam is #ecf heat units4 ,effect of ,increase of ,pressure on the ,boiling of ,water4--,now we have referred to diminution of pressure and its effect on the boiling-point of water1 and ,i may point out that by increasing the pressure1 such1 e4g41 as boiling water under a high pressure of steam1 you raise the boiling-point4 ,there are some industrial operations in which the action of certain boiling solutions is unavailing to effect certain decompositions or other ends when the boiling is carried on under the ordinary atmospheric pressure1 and boiling in closed and strong vessels under pressure must be resorted to4 ,take as an example the wood-pulp process for making paper from wood shavings4 ,boiling in open pans with caustic soda lye is insufficient to reduce the wood to pulp1 and so boiling in strong vessels under pressure is adopted4 ,the temperature of the solution rises far above #bab ,f4 7#ajj ,c474 ,let us see what may result chemically from the attainment of such high temperatures of water in our steam boilers working under high pressures4 ,if you blow ordinary steam at #bab ,f4 or #ajj ,c41 into fats or oils1 the fats and oils remain undecomposed2 but suppose you let fatty and oily matters of animal or vegetable origin1 such as lubricants1 get into your boiler feed-water and so into your boiler1 what will happen8 ,i have only to tell you that a process is patented for decomposing fats with superheated steam1 to drive or distil over the admixed fatty acids and glycerin1 in order to show you that in your boilers such greasy matters will be more or less decomposed4 ,fats are neutral as fats1 and will not injure the iron of the boilers2 but once decompose them and they are split up into an acid called a fat acid1 and glycerin4 ,that fat acid at the high temperature soon attacks your boilers and pipes1 and eats away the iron4 ,that is one of the curious results that may follow at such high temperatures4 ,mineral or hydrocarbon oils do not contain these fat acids1 and so cannot possibly1 even with high-pressure steam1 corrode the boiler metal4 ,effect of ,dissolved ,salts on the ,boiling of ,water4--,let us inquire what this effect is8 ,suppose we dissolve a quantity of a salt in water1 and then blow steam at #ajj ,c4 7#bab ,f47 into that water1 the latter will boil not at #bab ,f41 but at a higher temperature4 ,there is a certain industrial process ,i know of1 in course of which it is necessary first to maintain a vessel containing water1 by means of a heated closed steam coil1 at #bab ,f4 7#ajj ,c471 and at a certain stage to raise the temperature to about #cbg ,f4 7#afd ,c474 ,the pressure on the boiler connected with the steam coil is raised to nearly seven atmospheres1 and thus the heat of the high-pressure steam rises to #cbg ,f4 7#afd ,c471 and then a considerable quantity of nitrate of ammonium1 a crystallised salt1 is thrown into the water1 in which it dissolves4 ,strange to say1 although the water alone would boil at #bab ,f41 a strong solution in water of the ammonium nitrate only boils at #cbg ,f41 so that the effect of dissolving that salt in the water is the same as if the pressure were raised to seven atmospheres4 ,now let us1 as hat manufacturers1 learn a practical lesson from this fact4 ,we have observed that wool and fur fibres are injured by boiling in pure water1 and the heat has much to do with this damage2 but if the boiling take place in bichrome liquors or similar solutions1 that boiling will1 according to the strength of the solution in dissolved matters1 take place at a temperature more or less elevated above the boiling-point of water1 and so the damage done will be the more serious the more concentrated the liquors are1 quite independently of the nature of the substances dissolved in those liquors4 ,solution4--,we have already seen that when a salt of any kind dissolves in water1 heat is absorbed1 and becomes latent2 in other words1 cold is produced4 ,i will describe a remarkable example or experiment1 well illustrating this fact4 ,if you take some ,glauber's salt1 crystallised sulphate of soda1 and mix it with some hydrochloric acid 7or spirits of salt71 then so rapidly will the solution proceed1 and consequently so great will be the demand for heat1 that if a vessel containing water be put in amongst the dissolving salt1 the heat residing in that vessel and its water will be rapidly extracted1 and the water will freeze4 ,as regards solubility1 some salts and substances are much more quickly and easily dissolved than others4 ,we are generally accustomed to think that to dissolve a substance quickly we cannot do better than build a fire under the containing vessel1 and heat the liquid4 ,this is often the correct method of proceeding1 but not always4 ,thus it would mean simply loss of fuel1 and so waste of heat1 to do this in dissolving ordinary table salt or rock salt in water1 for salt is as soluble in cold water as in hot4 ,some salts are1 incredible though it may appear1 less soluble in boiling water than in cold4 ,water just above the freezing-point dissolves nearly twice as much lime as it does when boiling4 ,you see1 then1 that a knowledge of certain important facts like these may be so used as to considerably mitigate your coal bills1 under given circumstances and conditions4 ,,lecture ,,iv ,,water3 ,,its ,,chemistry ,,and ,,properties2 ,,impurities ,,and ,,their ,,action2 ,,tests ,,of ,,purity--,continued ,in the last lecture1 under the head of ,solution1 ,i mentioned that some salts1 some chemical substances1 are more soluble in water than others1 and that their solubilities under different circumstances of temperature vary in different ways4 ,however1 some salts and compounds are practically insoluble in water under any circumstances4 ,we now arrive at the important result known to chemists as the precipitation of insoluble compounds from solutions4 ,in order to define this result1 however1 we must1 of course1 first consider the circumstances of causation of the result4 ,let us take a simple case of chemical decomposition resulting in the deposition or precipitation of a substance from solution in the insoluble state4 ,we will take a salt you are probably acquainted with--sulphate of copper1 or bluestone1 and dissolve it in water1 and we have then the sulphate of copper in solution in water4 ,now suppose it is our desire to obtain from that solution all the copper by depositing it in some insoluble form4 ,we may accomplish this in several different ways1 relying on certain methods of decomposing that sulphate of copper4 ,one of the simplest and most economical is that adopted in a certain so-called wet method of extracting copper4 ,it is based on the fact that metallic iron has a greater tendency to combine in water solutions1 with the acids of copper salts1 than the copper has in those salts4 ,we simply need to place some scraps of iron in the copper sulphate solution to induce a change which may be represented as follows3 ,copper sulphate1 consisting of a combination of copper oxide with sulphuric acid1 yields with iron1 iron sulphate1 a combination of iron oxide with sulphuric acid1 and metallic copper4 ,the metallic copper produced separates in the form of a red coating on the iron scraps4 ,but we may also1 relying on the fact that oxide of copper is insoluble in water1 arrange for the deposition of the copper in that form4 ,this we can do by adding caustic soda to a hot solution of copper sulphate1 when we get the following change3 ,copper sulphate1 consisting of a combination of copper oxide with sulphuric acid1 yields with caustic soda1 sulphate of soda1 a combination of soda with sulphuric acid and oxide of copper4 ,oxide of copper is black1 and so in this decomposition what is called a black precipitate of that oxide is produced on adding the caustic soda4 ,but it might not suit us thus to deposit the copper from our solution2 we might desire to remove the sulphuric acid from the copper sulphate1 and leave the copper dissolved1 say in the form of a chloride4 ,we select1 then1 a compound which is a chloride1 and a chloride of a metal which forms an insoluble combination with sulphuric acid--chloride of barium1 say4 ,on adding this chloride of barium to sulphate of copper solution1 we get then a change which we might represent thus3 ,copper sulphate1 consisting of a combination of copper oxide with sulphuric acid1 yields with barium chloride1 which is a combination of barium and chlorine1 insoluble barium sulphate1 a combination of barium oxide with sulphuric acid1 and soluble copper chloride1 a combination of copper and chlorine4 ,this is called a double interchange4 ,now these are a few illustrations to show you what is meant by chemical decompositions4 ,one practical lesson1 of course1 we may draw is this3 ,we must have a care in dissolving bluestone or copper sulphate1 not to attempt it in iron pans1 and not to store or put verdigris into iron vessels1 or the iron will be acted upon1 and to some extent the copper salt will become contaminated with iron4 ,it will now be clear to you that1 as a solvent for bodies usually soluble in water1 water that is perfectly pure will be most suitable and not likely to cause any deposition or precipitation through chemical decompositions1 for there are no salts or other compounds in pure water to cause such changes4 ,such pure water is called soft water4 ,but the term is only a comparative one1 and water that is not quite1 but nearly pure--pure enough for most practical purposes--is also called soft water4 ,now rain is the purest form of natural water1 for it is a kind of distilled water4 ,water rises in vapour from the ocean as from a still1 and the salt and other dissolved matters remain behind4 ,meeting cold currents of air1 the vapours condense in rain1 and fall upon the earth4 ,after coming in contact with the earth1 the subsequent condition of that water entirely depends upon the character1 as regards solubility or insolubility1 of the substances composing the strata or layers of earth upon which it falls1 and through which it sinks4 ,if it meets with insoluble rocks--for all rocks are not insoluble--it remains1 of course1 pure and soft1 and in proportion as the constituents of rock and soil are soluble1 in that proportion does the water become hard4 ,we all know how dangerous acid is in water1 causing that water to act on many substances1 the iron of iron vessels1 the lime in soil or rock1 etc41 bringing iron and lime respectively into solution4 ,now the atmosphere contains carbonic acid1 and carbonic acid occurs in the earth1 being evolved by decomposing vegetation1 etc4 ,carbonic acid is also soluble to a certain1 though not large extent1 in water4 ,as we shall see1 water charged with carbonic acid attacks certain substances insoluble in pure water1 and brings them into solution1 and thus the water soon becomes hard4 ,about the close of the last lecture1 ,i said that lime is1 to a certain extent1 soluble in cold water4 ,the solution is called lime-water2 it might be called a solution of caustic lime4 ,when carbonic acid gas first comes in contact with such a solution1 chalk or carbonate of lime1 which is insoluble in water1 is formed1 and the lime is thus precipitated as carbonate4 ,supposing1 however1 we continued to pass carbonic acid gas into that water1 rendered milky with chalk powder1 very soon the liquid would clear1 and we should get once more a solution of lime1 but not caustic lime as it was at first1 simply now a solution of carbonate of lime in carbonic acid1 or a solution of bicarbonate of lime4 ,i will take some lime-water1 and ,i will blow through2 my breath contains carbonic acid1 and you will see the clear liquid become milky owing to separation of insoluble carbonate of lime1 or chalk4 ,i now continue blowing1 and at length that chalk dissolves with the excess of carbonic acid1 forming bicarbonate of lime4 ,this experiment explains how it is that water percolating through or running over limestone strata dissolves out the insoluble chalk4 ,such water1 hard from dissolved carbonate of lime1 can be softened by merely boiling the water1 for the excess of carbonic acid is then expelled1 and the chalk is precipitated again4 ,this would be too costly for the softening of large quantities of water1 the boiling process consuming too much coal1 and so another process is adopted4 ,quicklime1 or milk of lime1 is added to the water in the proper quantity4 ,this lime unites with the excess of carbonic acid holding chalk in solution1 and forms with it insoluble chalk1 and so all deposits together as chalk4 ,by this liming process1 also1 the iron of the water dissolved likewise in ferruginous streams1 etc41 by carbonic acid1 would be precipitated4 ,to show this deposition ,i will now add some clear lime-water to the solution ,i made of chalk with the carbonic acid of my breath1 and a precipitate is at once formed1 all the lime and carbonic acid together depositing as insoluble chalk4 ,hence clear lime-water forms a good test for the presence of bicarbonates of lime or iron in a water4 ,but water may be hard from the presence of other salts1 other lime salts4 ,for example1 certain parts of the earth contain a great deal of gypsum1 or natural sulphate of lime1 and this is soluble to some extent in water4 ,water thus hardened is not affected by boiling1 or the addition of lime1 and is therefore termed permanently hard water1 the water hardened with dissolved chalk being termed temporarily hard water4 ,i have said nothing of solid or undissolved impurities in water1 which are said to be in suspension1 for the separation of these is a merely mechanical matter of settling1 or filtration and settling combined4 ,as a general rule1 the water of rivers contains the most suspended and vegetable matter and the least amount of dissolved constituents1 whereas spring and well waters contain the most dissolved matters and the least suspended4 ,serious damage may be done to the dyer by either of these classes of impurities1 and ,i may tell you that the dissolved calcareous and magnesian impurities are the most frequent in occurrence and the most injurious4 ,i told you that on boiling1 the excess of carbonic acid holding chalk or carbonate of lime in solution as bicarbonate1 is decomposed and carbonate of lime precipitated4 ,you can at once imagine1 then1 what takes place in your steam boilers when such water is used1 and how incrustations are formed4 ,let us now inquire as to the precise nature of the waste and injury caused by hard and impure waters4 ,let us also take1 as an example1 those most commonly occurring injurious constituents1 the magnesian and calcareous impurities4 ,hard water only produces a lather with soap when that soap has effected the softening of the water1 and not till then4 ,in that process the soap is entirely wasted1 and the fatty acids in it form1 with the lime and magnesia1 insoluble compounds called lime and magnesia soaps1 which are sticky1 greasy1 adhesive bodies1 that precipitate and fix some colouring matters like a mordant4 ,we have in such cases1 then1 a kind of double mischief--7i7 waste of soap1 7ii7 injury to colours and dyes on the fabrics4 ,but this is not all1 for colours are precipitated as lakes1 and mordants also are precipitated1 and thus wasted1 in much the same sense as the soaps are4 ,now by taking a soap solution1 formed by dissolving a known weight of soap in a known volume of water1 and adding this gradually to hard water until a permanent lather is just produced1 we can directly determine the consumption of soap by such a water1 and ascertain the hardness4 ,such a method is called ,clark's process of determination or testing1 or ,clark's soap test4 ,we hear a great deal just now of soaps that will wash well in hard water1 and do wonders under any conditions2 but mark this fact1 none of them will begin to perform effective duty until such hard water has been rendered soft at the expense of the soap4 ,soaps made of some oils1 such as cocoa-nut oil1 for example1 are more soluble in water than when made of tallow1 etc41 and so they more quickly soften a hard water and yield lather1 but they are wasted1 as far as consumption is concerned1 to just the same extent as any other soaps4 ,they do not1 however1 waste so much time and trouble in effecting the end in view1 and1 as you know1 ,time is money in these days of work and competition4 ,after making a soap test as described above1 and knowing the quantity of water used1 it is1 of course1 easy to calculate the annual loss of soap caused by the hardness of the water4 ,the monthly consumption of soap in ,london is #a1jjj1jjj kilograms 7about #ajjj tons71 and it is estimated that the hardness of the ,thames water means the use of #bcj1jjj kilograms 7nearly #bcj tons7 more soap per month than would be necessary if soft water were used4 ,of course the soap manufacturers around ,london would not state that fact on their advertising placards1 but rather dwell on the victorious onslaught their particular brand will make on the dirt in articles to be washed1 in the teeth of circumstances that would be hopeless for any other brand of soap6 ,i have referred to the sticky and adhesive character of the compounds called lime soaps1 formed in hard waters4 ,now in washing and scouring wool and other fibres1 these sticky lime soaps adhere so pertinaciously that the fibres1 be they of wool1 silk1 or any other article1 remain in part untouched1 impermeable to mordant or colouring matter1 and hence irregular development of colour must be the consequence4 ,also an unnatural lustre or peculiar bloom may in parts arise1 ruining the appearance of the goods4 ,in some cases the lime soaps act like mordants1 attracting colouring matter unequally1 and producing patchy effects4 ,in the dye-baths in which catechu and tannin are used1 there is a waste of these matters1 for insoluble compounds are formed with the lime1 and the catechu and tannin are1 to a certain extent1 precipitated and lost4 ,some colours are best developed in an acid bath1 such as ,cochineal ,scarlet1 but the presence of the bicarbonate of lime tends to cause neutralisation of the acidity1 and so the dyeing is either retarded or prevented4 ,such mordants as red liquor and iron liquor1 which are acetates of alumina and iron respectively1 are also wasted1 a portion of them being precipitated by the lime1 thus weakening the mordant baths4 ,ferruginous ,impurities in ,water4--,iron in solution in water is very objectionable in dyeing operations4 ,when the iron is present as bicarbonate1 it acts on soap solutions like the analogous lime and magnesia compounds1 producing even worse results4 ,in wool scouring1 cotton bleaching1 and other processes requiring the use of alkaline carbonates1 ferric oxide is precipitated on the fibre4 ,a yellowish tinge is communicated to bleached fabrics1 and to dye bright and light colours is rendered almost out of the question4 ,you may always suspect iron to be present in water flowing from or obtained directly out of old coal pits1 iron mines1 or from places abounding in iron and aluminous shales4 ,moreover1 you sometimes1 or rather generally1 find that surface water draining off moorland districts1 and passing over ochre beds1 contains iron1 and on its way deposits on the beds of the streamlets conveying it1 and on the stones1 red or brown oxide of iron4 ,all water of this kind ought to be avoided in dyeing and similar operations4 ,the iron in water from old coal pits and shale deposits is usually present as sulphate due to the oxidation of pyrites1 a sulphuret or sulphide of iron4 ,water from heaths and moorlands is often acid from certain vegetable acids termed peaty acids4 ,this acidity places the water in the condition of a direct solvent for iron1 and that dissolved iron may cause great injury4 ,if such water cannot be dispensed with1 the best way is to carefully neutralise it with carbonate of soda2 the iron is then precipitated as carbonate of iron1 and can be removed4 ,contamination of ,water by ,factories4--,you may have neighbours higher up the stream than yourselves1 and these firms may cast forth as waste products substances which will cause immense waste and loss4 ,amongst these waste products the worst are those coming from chemical works1 paper works1 bleach works1 etc4 ,if the paper works be those working up wood pulp1 the pollutions of effluent water will be about as noxious as they well can be4 ,you will have gums and resins from the wood1 calcium chloride from the bleach vats1 acids from the sours2 resin1 and resin-soaps2 there may also be alumina salts present4 ,now alumina1 lime1 resin1 and resin-soaps1 etc41 precipitate dyestuffs1 and also soap2 if the water is alkaline1 some of the mordants used may be precipitated and wasted1 and very considerable damage done4 ,permanent hardness in water1 due to the presence of gypsum or sulphate of lime in solution1 may be remedied by addition of caustic soda4 ,of course1 if an alkaline water is objectionable in any process1 the alkali would have to be neutralised by the addition of some acid4 ,for use in boilers1 water might thus be treated1 but it would become costly if large quantities required such treatment4 ,water rendered impure by contaminations from dyehouses and some chemical works can be best purified1 and most cheaply1 by simple liming1 followed by a settling process4 ,if space is limited and much water is required1 instead of the settling reservoirs1 filtering beds of coke1 sand1 etc41 may be used4 ,the lime used neutralises acids in the contaminated and impure water1 precipitates colouring matters1 mordants1 soap1 albuminous matters1 etc4 ,tests of ,purity4--,i will now describe a few tests that may be of value to you in deciding as to what substances are contaminating any impure waters that may be at hand4 ,iron4--,if to a water you suspect to be hard from presence of carbonate of lime or carbonate of iron in solution in carbonic acid1 i4e4 as bicarbonates1 you add some clear lime-water1 and a white precipitate is produced1 you have a proof of carbonate of lime--hardness4 ,if the precipitate is brownish1 you may have1 also1 carbonate of iron4 ,i will now mention a very delicate test for iron4 ,such a test would be useful in confirmation4 ,if a very dilute solution of such iron water be treated with a drop or two of pure hydrochloric acid1 and a drop or so of permanganate of potash solution or of ,condy's fluid1 and after that a few drops of yellow prussiate of potash solution be added1 then a blue colour 7,prussian blue71 either at once or after standing a few hours1 proves the presence of iron4 ,copper4--,sometimes1 as in the neighbourhood of copper mines or of some copper pyrites deposits1 a water may be contaminated with small quantities of copper4 ,the yellow prussiate once more forms a good test1 but to ensure the absence of free mineral acids1 it is first well to add a little acetate of soda solution4 ,a drop or two of the prussiate solution then gives a brown colour1 even if but traces of copper are present4 ,magnesia4--,suppose lime and magnesia are present4 ,you may first evaporate to a small bulk1 adding a drop of hydrochloric acid if the liquid becomes muddy4 ,then add ammonia and ammonium oxalate1 when lime alone is precipitated as the oxalate of lime4 ,filter through blotting paper1 and to the clear filtrate add some phosphate of soda solution4 ,a second precipitation proves the presence of magnesia4 ,sulphates4--,a solution of barium chloride and dilute hydrochloric acid gives a white turbidity4 ,chlorides4--,a solution of silver nitrate and nitric acid gives a white curdy precipitate4 ,test for ,lead in ,drinking ,water4--,i will1 lastly1 give you a test that will be useful in your own homes to detect minute quantities of lead in water running through lead pipes4 ,place a large quantity of the water in a glass on a piece of white paper1 and add a solution of sulphuretted hydrogen and let stand for some time4 ,a brown colour denotes lead4 ,of course copper would also yield a brown coloration1 but ,i am supposing that the circumstances preclude the presence of copper4 ,i have already said that rain water is the purest of natural waters2 it is so soft1 and free from dissolved mineral matters because it is a distilled water4 ,in distilling water to purify it1 we must be very careful what material we use for condensing the steam in1 since it is a fact probably not sufficiently well known1 that the softer and purer a water is1 the more liable it is to attack lead pipes4 ,hence a coil of lead pipe to serve as condensing worm would be inadmissible4 ,such water as ,manchester water1 and ,glasgow water from ,loch ,katrine still more so1 are more liable to attack lead pipes than the hard ,london waters4 ,to illustrate this fact1 we will distil some water and condense in a leaden worm1 then1 on testing the water with our reagent1 the sulphuretted hydrogen water1 a brown colour is produced1 showing the presence of lead4 ,on condensing in a block tin worm1 however1 no tin is dissolved1 so tin is safer and better as the material for such a purpose than lead4 ,filtration4--,we hear a great deal about filtration or filters as universal means of purifying water4 ,filtration1 we must remember1 will1 as a rule1 only remove solid or suspended impurities in water4 ,for example1 if we take some ivory black or bone black1 and mix it with water and afterwards filter the black liquid through blotting-paper1 the bone black remains on the paper1 and clear1 pure water comes through4 ,filtering is effective here4 ,if we take some indigo solution1 however1 and pour it on to the filter1 the liquid runs through as blue as it was when poured upon the filter4 ,filtering is ineffective here1 and is so generally with liquids containing matters dissolved in them4 ,but ,i said generally1 and so the question is suggested--,will filtration of any kind remove matters in solution8 ,this question ,i will1 in conclusion1 try to answer4 ,bone charcoal1 or bone black1 has a wonderful attraction for many organic matters such as colours1 dyes1 and coloured impurities like those in peat water1 raw sugar solutions1 etc4 ,for example1 if we place on a paper filter some bone black1 and filter through it some indigo solution1 after first warming the latter with some more of the bone black1 the liquid comes through clear1 all the indigo being absorbed in some peculiar way1 difficult to explain1 by the bone black1 and remaining on the filter4 ,this power of charcoal also extends to gases1 and to certain noxious dissolved organic impurities1 but it is never safe to rely too much on such filters1 since the charcoal can at length become charged with impurities1 and gradually cease to act4 ,these filters need cleaning and renewing from time to time4 ,,lecture ,v ,,acids ,,and ,,alkalis ,properties of ,acids and ,alkalis4--,the name acids is given to a class of substances1 mostly soluble in water1 having an acid or sour taste1 and capable of turning blue litmus solution red4 ,all acids contain one or more atoms of hydrogen capable of being replaced by metals1 and when such hydrogen atoms are completely replaced by metals1 there result so-called neutral or normal salts1 that is1 neutral substances having no action on litmus solution4 ,these salts can also be produced by the union of acids with equivalent quantities of certain metallic oxides or hydroxides1 called bases1 of which those soluble in water are termed alkalis4 ,alkalis have a caustic taste1 and turn red litmus solution blue4 ,in order to explain what is called the law of equivalence1 ,i will remind you of the experiment of the previous lecture1 when a piece of bright iron1 being placed in a solution of copper sulphate1 became coated with metallic copper1 an equivalent weight of iron meanwhile suffering solution as sulphate of iron4 ,according to the same law1 a certain weight of soda would always require a certain specific equivalent weight of an acid1 say hydrochloric acid1 to neutralise its alkaline or basic properties1 producing a salt4 ,the specific gravities of acids and alkalis in solution are made use of in works1 etc41 as a means of ascertaining their strengths and commercial values4 ,tables have been carefully constructed1 such that for every degree of specific gravity a corresponding percentage strength of acidity and alkalinity may be looked up4 ,the best tables for this purpose are given in ,lunge and ,hurter's ,alkali-,makers' ,pocket-,book1 but for ordinary purposes of calculation in the works or factory1 a convenient relationship exists in the case of hydrochloric acid between specific gravity and percentage of real acid1 such that specific gravity as indicated by ,twaddell's hydrometer directly represents percentage of real acid in any sample of hydrochloric acid4 ,the point at which neutralisation of an acid by alkali or vice vers just takes place is ascertained very accurately by the use of certain sensitive colours4 ,at first litmus and cochineal tinctures were used1 but in testing crude alkalis containing alumina and iron1 it was found that lakes were formed with these colours1 and they become precipitated in the solution1 and so no longer sensitive4 ,the chemist was then obliged to resort to certain sensitive coal-tar colours1 which did not1 as the dyer and printer knew1 form lakes with alumina and iron1 such as methyl orange1 fluorescein1 ,congo red1 phenolphthalein1 and so forth4 ,for determining the alkalimetric strength of commercial sodas1 a known weight of the sample is dissolved in water1 and a few drops of a solution of methyl orange are added1 which colour the solution yellow or orange4 ,into this solution is then run1 from a burette or graduated tube1 a standard solution of an acid1 that is1 a solution prepared by dissolving a known weight of an acid1 say hydrochloric acid1 in a known volume of water4 ,the acid is run in gradually until the yellow colour changes to pink1 at which point the volume of acid used is noted4 ,knowing the weight of acid contained in this volume of standard acid1 and having regard to the law of equivalence mentioned above1 it is an easy matter to calculate the amount of alkali equivalent to the acid used1 and from this the alkali contained in the sample4 ,sulphuric ,acid4--,the first process for manufacturing sulphuric acid or vitriol was by placing some burning sulphur in a closed vessel containing some water4 ,the water absorbed the acid formed by the burning sulphur4 ,it was next discovered that by mixing with the sulphur some nitre1 much more sulphuric acid could be produced per given quantity of brimstone4 ,at first large glass carboys were used1 but in #agdf the carboys were replaced by chambers of lead containing water at the bottom1 and in these lead chambers the mixture of sulphur and nitre was burnt on iron trays4 ,next1 although gradually1 the plant was divided into two portions--a furnace for burning the sulphur1 and a chamber for receiving the vapours4 ,the system was thus developed into the one followed at the present time4 ,the sulphur1 or1 in most cases1 cupreous iron pyrites 7a combination of iron and copper with sulphur71 is burned in specially constructed kilns or furnaces1 and the hot gases1 consisting essentially of sulphur dioxide with the excess of air1 pass through flues in which are placed cast-iron nitre pots containing a mixture of nitre 7sodium nitrate7 and vitriol4 ,the gases thus become mixed with nitrous fumes or gaseous oxides of nitrogen1 and1 after cooling1 are ready for mixing with steam or water spray in the lead chambers in which the vitriol is produced4 ,these oxides of nitrogen enable the formation of sulphuric acid to take place more quickly by playing the part of oxygen-carriers4 ,sulphuric acid is formed by the union of oxygen with sulphur dioxide and water2 the oxides of nitrogen combine with the oxygen of the air present in the chambers1 then give up this oxygen to the sulphur dioxide and water or steam to form sulphuric acid1 again combine with more oxygen1 and so on4 ,the exact processes or reactions are of course much more complicated1 but the above represents what is practically the ultimate result4 ,it is evident that the gases leaving the last lead chamber in which the formation of vitriol is effected1 must still contain nitrous fumes1 and it becomes a matter of importance to recover them1 so that they can be used over again4 ,to effect this object1 use is made of the solubility of nitrous fumes in strong vitriol4 ,the gases from the last lead chamber of the series are passed through what is called a ,gay-,lussac tower 7the process was invented by the eminent ,french chemist ,gay-,lussac71 which is a tower made of lead1 supported by a wooden framework1 and filled with coke or special stoneware packing1 over which strong vitriol is caused to flow4 ,the vitriol dissolves the nitrogen oxides1 and so-called nitrous vitriol flows out at the base of the tower4 ,the recovery of the nitrogen compounds from the nitrous vitriol is effected in ,glover towers 7the invention of ,john ,glover of ,newcastle71 which also serve to concentrate to some extent the weak acid produced in the lead chambers1 and to cool the hot gases from the sulphur burners or pyrites kilns4 ,the weak chamber acid is mixed with the nitrous vitriol from the ,gay-,lussac tower1 and the mixture is pumped to the top of the ,glover tower1 which is of similar construction to the ,gay-,lussac tower1 but is generally packed with flints4 ,this ,glover tower is placed between the sulphur burners or pyrites kilns and the first lead chamber4 ,the nitrous vitriol passing down the tower meets the hot gases from the kilns1 and a threefold object is effected3 7#a7 ,the nitrous fumes are expelled from the nitrous vitriol1 and are carried into the chambers1 to again play the part of oxygen-carriers2 7#b7 the weak chamber acid which was mixed with the nitrous vitriol is concentrated by the hot kiln gases2 and 7#c7 the hot gases themselves are cooled4 ,the acid from the ,glover tower is purified by special treatment--for example1 the arsenic may be removed1 after precipitation with sulphuretted hydrogen1 in the form of insoluble arsenic sulphide1--and the purified acid is concentrated by heating in glass or platinum vessels4 ,a considerable amount of sulphuric acid is now made by the so-called contact process1 in which sulphur dioxide and oxygen unite to form sulphuric acid in presence of a heated contact substance1 usually some form of finely-divided platinum4 ,nitric ,acid4--,this acid is usually prepared by distilling a mixture of sodium nitrate and vitriol in cast-iron retorts or pots1 the nitric acid being collected in stoneware vessels connected one with another1 or1 as is more generally the case at the present time1 in condensing apparatus consisting of stoneware pipes or coils cooled by water4 ,the effluent gases are passed through a scrubber in order to free them from the last traces of acid before discharging them into the atmosphere4 ,hydrochloric ,acid4--,the greater part of the hydrochloric acid manufactured in ,great ,britain is obtained as an intermediate product in the ,leblanc alkali process1 which will presently be described1 being produced by heating common salt with vitriol4 ,a large quantity is1 however1 also produced by the so-called direct process of ,hargreaves ,robinson1 which is1 in principle1 the same method as that employed in the ,leblanc process1 except that the intermediate product1 vitriol1 is not separated4 ,it consists essentially in passing the hot gases from pyrites kilns1 as used in the manufacture of vitriol1 through large cast-iron vessels containing common salt heated to a high temperature4 ,various physical conditions must be complied with in order to make the process a success4 ,for example1 the salt is used in the form of moulded hard porous cakes made from a damp mixture of common salt and rock salt4 ,the cast-iron vessels must be heated uniformly1 and the hot pyrites kiln gases must be passed downwards through the salt in order to ensure uniform distribution4 ,the hydrochloric acid is condensed in stoneware pipes connected with towers packed with coke or stoneware4 ,alkali3 ,leblanc ,process4--,the manufacture of vitriol1 as ,i have described it to you1 is the first step in the ,leblanc process4 ,the next stage consists in the manufacture of sodium sulphate 7salt-cake7 and hydrochloric acid from the sulphuric acid and common salt2 this is called the salt-cake process4 ,the production of salt-cake or crude sodium sulphate is carried out in two stages4 ,a large covered iron pan1 called the decomposing pan or salt-cake pot1 is mounted in one part of the salt-cake furnace1 and alongside it is the hearth or bed on which the second stage of the process1 the drying or roasting1 is effected4 ,the mixture of common salt and vitriol is charged into the salt-cake pot1 which is heated by a fire below4 ,when from two-thirds to three-quarters of the hydrochloric acid has been expelled from the charge1 the mass acquires the consistence of thick dough1 and at this stage it is raked out of the pan on to the roasting hearth alongside1 where the decomposition is completed by means of flames playing directly on to the top of the charge4 ,the hydrochloric acid evolved during the process is condensed in much the same manner as in the process of ,hargreaves ,robinson previously described4 ,it is a curious fact that in the earlier years of the ,leblanc process1 hydrochloric acid1 or spirits of salt1 as it is frequently called1 was a by-product that required all the vigilance of the alkali-works inspectors to prevent it being allowed to escape from the chimneys in more than a certain small regulated amount4 ,now1 it is the principal product2 indeed1 the ,leblanc alkali maker may be said to subsist on that hydrochloric acid1 as his chief instrument for producing chloride of lime or bleaching powder4 ,mechanical furnaces are now used to a large extent for the salt-cake process4 ,they consist broadly of a large revolving furnace-hearth or bed1 on to which the mixture of salt and vitriol is charged1 and on which it is continuously agitated1 and gradually moved to the place of discharge1 by rakes or the like1 operated by suitable machinery4 ,the next stage of the ,leblanc process is the manufacture of black ash1 or crude sodium carbonate4 ,this is usually done in large cylindrical revolving furnaces1 through1 which flames from a fire-grate1 or from the burning of gaseous fuel1 pass2 the waste heat is utilised for boiling down black ash liquor1 obtained by lixiviating the black ash4 ,a mixture of salt-cake1 limestone or chalk 7calcium carbonate71 and powdered coal or coal slack is charged into the revolving cylinder2 during the process the mass becomes agglomerated1 and the final product is what is known as a black-ash ball1 consisting chiefly of crude sodium carbonate and calcium sulphide1 but containing smaller quantities of many other substances4 ,the soda ash or sodium carbonate is obtained from the black ash by lixiviating with water1 and after various purification processes1 the solution is boiled down1 as previously stated1 by the waste heat of the black-ash furnace4 ,the alkali is sold in various forms as soda ash1 soda crystals1 washing soda1 etc4 ,caustic soda is manufactured from solution of carbonate of soda by causticising1 that is1 treatment with caustic lime or quicklime4 ,it will have been noticed that one of the chief reagents in the ,leblanc process is the sulphur used in the form of brimstone or as pyrites for making vitriol in the first stage2 this sulphur goes through the entire process2 from the vitriol it goes to form a constituent of the salt-cake1 and afterwards of the calcium sulphide contained in the black ash4 ,this calcium sulphide remains as an insoluble mass when the carbonate of soda is extracted from the black ash1 and forms the chief constituent of the alkali waste1 which until the year #ahhj could be seen in large heaps around chemical works4 ,now1 however1 by means of treatment with kiln gases containing carbonic acid1 the sulphur is extracted from the waste in the form of hydrogen sulphide1 which is burnt to form vitriol1 or is used for making pure sulphur2 and so what was once waste is now a source of profit4 ,ammonia-,soda ,process of ,alkali ,manufacture4--,this process depends upon the fact that when carbonic acid is forced1 under pressure1 into a saturated solution of ammonia and common salt1 sodium bicarbonate is precipitated1 whilst ammonium chloride or sal-ammoniac remains dissolved in the solution4 ,the reaction was discovered in #ahcf by a ,scotch chemist named ,john ,thom1 and small quantities of ammonia-soda were made at that time by the firm of ,mc,naughton ,thom4 ,the successful carrying out of the process on the large scale depends principally upon the complete recovery of the expensive reagent1 ammonia1 and this problem was only solved within comparatively recent years by ,solvay4 ,the process has been perfected and worked with great success in ,england by ,messrs4 ,brunner1 ,mond1 ,co41 and has proved a successful rival to the ,leblanc process4 ,alkali is also produced to some extent by electrolytic processes1 depending upon the splitting up of a solution of common salt into caustic soda and chlorine by the use of an electric current4 ,,lecture ,,vi ,,boric ,,acid1 ,,borax1 ,,soap ,boric ,acid4--,at ordinary temperatures and under ordinary conditions boric acid is a very weak acid1 but like silicic and some other acids1 its relative powers of affinity and combination become very much changed at high temperatures2 thus1 fused and strongly heated boric acid can decompose carbonates and even sulphates1 and yet a current of so weak an acid as hydrogen sulphide1 passed through a strong solution of borax1 will decompose it and set free boric acid4 ,boric acid is obtained chiefly from ,italy4 ,in a tract of country called the ,maremma of ,tuscany1 embracing an area of about forty square miles1 are numerous chasms and crevices1 from which hot vapour and heated gases and springs of water spurt4 ,the steam issuing from these hot springs contains small quantities of boric acid1 that acid being one of those solid substances distilling to some extent in a current of steam4 ,the steam vapours thus bursting forth1 owing to some kind of constant volcanic disturbance1 are also more or less laden with sulphuretted hydrogen gas1 communicating a very ill odour to the neighbourhood4 ,these phenomena were at first looked upon by the people as the work of the devil1 and priestly exorcisms were in considerable request in the hope of quelling them1 very much as a great deal of the mere speech-making at the present time in ,england on foreign competition and its evils1 and the dulness of trade1 the artificial combinations to keep up prices1 to reduce wages1 general lamentation1 etc41 are essayed in the attempt to charm away bad trade4 ,at length a kind of prophet arose of a very practical character in the form of the late ,count ,lardarel1 who1 mindful of the fact that the chemist ,hffer1 in the time of the ,grand ,duke ,leopold ,i41 had discovered boric acid in the volcanic steam jets1 looked hopefully beyond the exorcisms of the priests and the superstitions of the people to a possible blessing contained in what appeared to be an unholy confusion of ,nature4 ,he constructed tanks of from #ajj to #ajjj ft4 in diameter and #g to #bj ft4 in depth1 of such a kind that the steam jets were surrounded by or contained in them1 and thus the liquors formed by condensation became more and more concentrated4 ,these tanks were arranged at different levels1 so that the liquors could be run off from one to the other1 and finally to settling cisterns4 ,subsequently the strong liquors were run to lead-lined1 wooden vats1 in which the boric acid was crystallised out4 ,had the industry depended on the use of fuel it could never have developed1 but ,count ,lardarel ingeniously utilised the heat of the steam for all the purposes1 and neither coal nor wood was required4 ,where would that ,tuscan boric acid industry have been now had merely the lamentations of landowners1 fears of the people1 and exorcisms of the priests been continued8 ,instead of being the work of the arch-enemy of mankind1 was not it rather an incitement to a somewhat high and difficult step in an upward direction towards the attainment1 on a higher platform of knowledge and skill1 of a blessing for the whole province of ,tuscany8 ,what was true in the history of that industry and its development is every whit as true of the much-lamented slackening of trade through foreign competition or other causes now in this country1 and coming home to yourselves in the hat-manufacturing industry4 ,the higher platform to which it was somewhat difficult to step up1 but upon which the battle must be fought and the victory won1 was one of a higher scientific and technological education and training4 ,the chemist ,hffer made the discovery of boric acid in the vapours1 they would no doubt take note2 but ,hffer went no further2 and it needed the man of both educated and practical mind like ,count ,lardarel to turn the discovery to account and extract the blessing4 ,in like manner it was clear that in our educational schemes for the benefit of the people1 there must not only be the scientific investigator of abstract truth1 but also the scientific technologist to point the way to the practical realisation of tangible profit4 ,moreover1 and a still more important truth1 it is the scientific education of the proprietors and heads we want--educated capital rather than educated workmen4 ,borax4--,a good deal of the ,tuscan boric acid is used in ,france for the manufacture of borax1 which is a sodium salt of boric acid4 ,borax is also manufactured from boronitrocalcite1 a calcium salt of boric acid1 which is found in ,chili and other parts of ,south ,america4 ,the crude boronitrocalcite or tiza is boiled with sodium carbonate solution1 and1 after settling1 the borax is obtained by crystallisation4 ,borax itself is found in ,california and ,nevada1 ,u4,s4,a41 and also in ,peru1 ,ceylon1 ,china1 ,persia1 and ,thibet4 ,the commercial product is obtained from the native borax 7known as tincal7 by dissolving in water and allowing the solution to crystallise4 ,the ,peruvian borax sometimes contains nitre4 ,for testing the purity of refined borax the following simple tests will usually suffice4 ,a solution of the borax is made containing #a part of borax to #ej parts of water1 and small portions of the solution are tested as follows3 ,heavy metals 7lead1 copper1 etc474--,on passing sulphuretted hydrogen into the solution1 no coloration or precipitate should be produced4 ,calcium ,salts4--,the solution should not give a precipitate with ammonium oxalate solution4 ,carbonates4--,the solution should not effervesce on addition of nitric or hydrochloric acid4 ,chlorides4--,no appreciable precipitate should be produced on addition of silver nitrate solution and nitric acid4 ,sulphates4--,no appreciable precipitate should be produced on adding hydrochloric acid and barium chloride4 ,iron4--#ej c4c4 of the solution should not immediately be coloured blue by #je c4c4 of potassium ferrocyanide solution4 ,soap4--,soap is a salt in the chemical sense1 and this leads to a wider definition of the term salt or saline compound4 ,fats and oils1 from which soaps are manufactured1 are a kind of quasi salts1 composed of a fatty acid and a chemical constant1 if ,i may use the term1 in the shape of base1 namely1 glycerin4 ,when these fats and oils1 often called glycerides1 are heated with alkali1 soda1 a true salt of the fatty acid and soda is formed1 and this is the soap1 whilst the glycerin remains behind in the spent soap lye4 ,now glycerin is soluble in water containing dissolved salt 7brine71 whilst soap is insoluble1 though soluble in pure water4 ,the mixture of soap and glycerin produced from the fat and soda is therefore treated with brine1 a process called cutting the soap4 ,the soap separates out in the solid form as a curdy mass1 which can be easily separated4 ,certain soaps are able to absorb a large quantity of water1 and yet appear quite solid1 and in purchasing large quantities of soap it is necessary1 therefore1 to determine the amount of water present4 ,this can be easily done by weighing out ten or twenty grams of the soap1 cut in small pieces1 into a porcelain dish and heating over a gas flame1 whilst keeping the soap continually stirred1 until a glass held over the dish no longer becomes blurred by escaping steam4 ,after cooling1 the dry soap is weighed1 and the loss of weight represents the amount of moisture4 ,i have known cases where soap containing about #hc per cent4 of water has been sold at the full market price4 ,some soaps also contain more alkali than is actually combined with the fatty acids of the soap1 and that excess alkali is injurious in washing silks and scouring wool1 and is also not good for the skin4 ,the presence of this free or excess alkali can be at once detected by rubbing a little phenolphthalein solution on to the freshly-cut surface of a piece of soap2 if free alkali be present1 a red colour will be produced4 ,,lecture ,,vii ,,shellac1 ,,wood ,,spirit1 ,,and ,,the ,,stiffening ,,and ,,proofing ,,process ,shellac4--,the resin tribe1 of which shellac is a member1 comprises vegetable products of a certain degree of similarity4 ,they are mostly solid1 glassy-looking substances insoluble in water1 but soluble in alcohol and wood spirit4 ,in many cases the alcoholic solutions show an acid reaction4 ,the resins are partly soluble in alkalis1 with formation of a kind of alkali salts which we may call resin-soaps4 ,shellac is obtained from the resinous incrustation produced on the bark of the twigs and branches of various tropical trees by the puncture of the female lac insect 7,taccardia lacca74 ,the lac is removed from the twigs by beating in water2 the woody matter floats to the surface1 and the resin sinks to the bottom1 and when removed forms what is known as seed-lac4 ,formerly1 the solution1 which contains the colouring matter dissolved from the crude stick-lac1 was evaporated for recovery of the so-called lac-dye1 but the latter is no longer used technically4 ,the seed-lac is bleached by boiling with sodium or potassium carbonate1 alum1 or borax1 and then1 if it is not pale enough1 is further bleached by exposure to sunlight4 ,it is now dried1 melted1 and mixed with a certain proportion of rosin or of orpiment 7a sulphide of arsenic7 according to the purpose for which it is desired4 ,after further operations of melting and straining1 the lac is melted and spread into thin sheets to form ordinary shellac1 or is melted and dropped on to a smooth surface to form button-lac4 ,ordinary shellac almost invariably contains some rosin1 but good button-lac is free from this substance4 ,the presence of #e per cent4 of rosin in shellac can be detected by dissolving in a little alcohol1 pouring the solution into water1 and drying the fine impalpable powder which separates4 ,this powder is extracted with petroleum spirit1 and the solution shaken with water containing a trace of copper acetate4 ,if rosin be present1 the petroleum spirit will be coloured emerald-green4 ,borax1 soda crystals1 and ammonia are all used to dissolve shellac1 and it may be asked3 ,which of these is least injurious to wool8 and why8 ,how is their action modified by the presence of dilute sulphuric acid in the wool8 ,i would say that soda crystals and ammonia are alkalis1 and if used strong1 are sure to do a certain amount of injury to the fibre of wool1 and more if used hot than cold4 ,of the two1 the ammonia will have the least effect1 especially if dilute1 but borax is better than either4 ,the influence of a little sulphuric acid in the wool would be in the direction of neutralising some of the ammonia or soda1 and shellac1 if dissolved in the alkalis1 would be to some extent precipitated on the fibre1 unless the alkali1 soda or ammonia1 were present in sufficient excess to neutralise that sulphuric acid and to leave a sufficient balance to keep the shellac in solution4 ,borax1 which is a borate of soda1 would be so acted on by the sulphuric acid that some boric acid would be set free1 the sulphuric acid robbing some of that borax of its soda4 ,this boric acid would not be nearly so injurious to wool as carbonate of soda or ammonia would4 ,the best solvent for shellac1 however1 in the preparation of the stiffening and proofing mixture for hats1 is probably wood spirit or methylated spirit4 ,a solution of shellac in wood spirit is indeed used for the spirit-proofing of silk hats1 and to some extent of felt hats1 and on the whole the best work1 ,i believe1 is done with it4 ,moreover1 borax is not a cheap agent1 and being non-volatile it is all left behind in the proofed material1 whereas wood spirit or methylated spirit is a volatile liquid1 i4e4 a liquid easily driven off in vapour1 and after application to the felt it may be almost all recovered again for re-use4 ,in this way ,i conceive the use of wood spirit would be both more effective and also cheaper than that of borax1 besides being most suitable in the case of any kind of dyes and colours to be subsequently applied to the hats4 ,wood ,spirit4--,wood spirit1 the pure form of which is methyl alcohol1 is one of the products of the destructive distillation of wood4 ,the wood is distilled in large iron retorts connected to apparatus for condensing the distillation products4 ,the heating is conducted slowly at first1 so that the maximum yield of the valuable products--wood acid 7acetic acid7 and wood spirit--which distil at a low temperature1 is obtained4 ,when the condensed products are allowed to settle1 they separate into two distinct layers1 the lower one consisting of a thick1 very dark tar1 whilst the upper one1 much larger in quantity1 is the crude wood acid 7containing also the wood spirit71 and is reddish-yellow or reddish-brown in colour4 ,this crude wood acid is distilled1 and the wood spirit which distils off first is collected separately from the acetic acid which afterwards comes over4 ,the acid is used for the preparation of alumina and iron mordants 7see next lecture71 or is neutralised with lime1 forming grey acetate of lime1 from which1 subsequently1 pure acetic acid or acetone is prepared4 ,the crude wood spirit is mixed with milk of lime1 and after standing for several hours is distilled in a rectifying still4 ,the distillate is diluted with water1 run off from any oily impurities which are separated1 and re-distilled once or twice after treatment with quicklime4 ,stiffening and ,proofing ,process4--,before proceeding to discuss the stiffening and proofing of hat forms or bodies1 it will be well to point out that it was in thoroughly grasping the importance of a rational and scientific method of carrying out this process that ,continental hat manufacturers had been able to steal a march upon their ,english rivals in competition as to a special kind of hat which sold well on the ,continent4 ,there are1 or ought to be1 three aims in the process of proofing and stiffening1 all the three being of equal importance4 ,these are3 first1 to waterproof the hat-forms2 second1 to stiffen them at the same time and by the same process2 and the third1 the one the importance of which ,i think ,english hat manufacturers have frequently overlooked1 at least in the past1 is to so proof and stiffen the hat-forms as to leave them in a suitable condition for the subsequent dyeing process4 ,in proofing the felt1 the fibres become varnished over with a kind of glaze which is insoluble in water1 and this varnish or proof is but imperfectly removed from the ends of the fibres on the upper surface of the felt4 ,the consequence is a too slight penetration of the dyestuff into the inner pores of the fibres2 indeed1 in the logwood black dyeing of such proofed felt a great deal of the colour becomes precipitated on the outside of the fibres--a kind of process of smudging-on of a black pigment taking place4 ,the subsequent greening of the black hats after a short period of wear is simply due to the ease with which such badly fixed dye rubs off1 washes off1 or wears off1 the brownish or yellowish substratum which gradually comes to light1 causing a greenish shade to at length appear4 ,if we examine under the microscope a pure unproofed fur fibre1 its characteristic structure is quite visible4 ,examination of an unproofed fibre dyed with logwood black shows again the same characteristic structure with the dye inside the fibre1 colouring it a beautiful bluish-grey tint1 the inner cellular markings being black4 ,a proofed fur fibre1 on the other hand1 when examined under the microscope1 is seen to be covered with a kind of translucent glaze1 which completely envelops it1 and prevents the beautiful markings showing the scaly structure of the fibre from being seen4 ,finally1 if we examine microscopically a proofed fibre which has been dyed1 or which we have attempted to dye1 with logwood black1 we find that the fibre presents an appearance similar to that of rope which has been drawn through some black pigment or black mud1 and then dried4 ,it is quite plain that no lustrous appearance or good finish can be expected from such material4 ,now how did the ,continental hat manufacturers achieve their success1 both as regards dyeing either with logwood black or with coal-tar colours1 and also getting a high degree of finish8 ,they attained their object by rubbing the proofing varnish on the inside of the hat bodies1 in some cases first protecting the outside with a gum-varnish soluble in water but resisting the lac-varnish rubbed inside4 ,thus the proofing could never reach the outside4 ,on throwing the hat bodies1 thus proofed by a logical and scientific process1 into the dye-bath1 the gums on the outer surface are dissolved and removed1 and the dye strikes into a pure1 clean fibre1 capable of a high degree of finish4 ,this process1 however1 whilst very good for the softer hats used on the ,continent1 is not so satisfactory for the harder1 stiffer headgear demanded in ,great ,britain4 ,what was needed was a process which would allow of a through-and-through proofing and stiffening1 and also of satisfactory dyeing of the stiffened and proofed felt4 ,this was accomplished by a process patented in #ahhg by ,mr4 ,f4,w4 ,cheetham1 and called the veneering process4 ,the hat bodies1 proofed as hard as usual1 are thrown into a bumping machine containing hot water rendered faintly acid with sulphuric acid1 and mixed with short-staple fur or wool1 usually of a finer quality than that of which the hat bodies are composed4 ,the hot acid water promotes in a high degree the felting powers of the short-staple wool or fur1 and1 to a lesser extent1 the thinly proofed ends of the fibres projecting from the surfaces of the proofed hat-forms4 ,thus the short-staple wool or fur felts itself on to the fibres already forming part of the hat bodies1 and a new layer of pure1 unproofed wool or fur is gradually wrought on to the proofed surface4 ,the hat-forms are then taken out and washed1 and can be dyed with the greatest ease and with excellent results1 as will be seen from the accompanying illustration 7see ,fig4 #ae74 ,this successful invention emphasises the value of the microscope in the study of processes connected with textile fibres4 ,i would strongly advise everyone interested in hat manufacturing or similar industries to make a collection of wool and fur fibres1 and mount them on microscope slides so as to form a kind of index collection for reference4 ,illustration3 ,,fig4 #ae4 #a4 ,natural wool fibre unproofed4 #b4 ,wool fibre showing proof on surface1 filling up the cells and rendering the same dye-proof4 #c4 ,fur fibre from surface of veneered felt1 showing dye deposited in cells and on the surface1 bright and lustrous4 #d4 ,wool fibre as in ,no4 #b1 with dye deposited on surface of proof4 #e4 ,section of proofed and veneered body1 showing unproofed surface4 #f4 ,section of proofed body without veneer4 ,,lecture ,,viii ,,mordants3 ,,their ,,nature ,,and ,,use ,the name or word mordant indicates the empiricism1 or our old friend the rule of thumb1 of the age in which it was first created and used4 ,it serves as a landmark of that age1 which1 by the way1 needed landmarks1 for it was an age of something between scientific twilight and absolute darkness4 ,morder in ,french1 derived from the ,latin mordere1 means to bite1 and formerly the users of mordants in dyeing and printing believed their action to be merely a mechanical action1 that is1 that they exerted a biting or corroding influence1 serving to open the pores of the fabrics1 and thus to give more ready ingress to the colour or dye4 ,most mordants are salts1 or bodies resembling salts1 and hence we must commence our study of mordants by a consideration of the nature of salts4 ,i have already told you that acids are characterised by what we term an acid reaction upon certain vegetable and artificial colours1 whilst bases or basic substances in solution1 especially alkalis1 restore those colours1 or turn them to quite another shade2 the acids do the one thing1 and the alkalis and soluble bases do the opposite4 ,the strongest and most soluble bases are the alkalis--soda1 potash1 and ammonia4 ,you all know1 probably1 that a drop of vitriol allowed to fall on a black felt hat will stain that hat red if the hat has been dyed with logwood black2 and if you want to restore the black1 you can do this by touching the stain with a drop of strong ammonia4 ,but the use of a black felt hat as a means of detecting acidity or alkalinity would not commend itself to an economic mind1 and we find a very excellent reagent for the purpose in extract of litmus or litmus tincture1 as well as in blotting paper stained therewith4 ,the litmus is turned bright red by acids and blue by alkalis4 ,if the acid is exactly neutralised by1 that is combined with1 the alkaline base to form fully neutralised salts1 the litmus paper takes a purple tint4 ,coloured reagents such as litmus are termed indicators4 ,a substance called phenolphthalein1 a coal-tar product1 is a very delicate indicator2 it is more sensitive to acids than litmus is4 ,now there are some salts which contain a preponderance of acid in their composition1 i4e4 in which the acid has not been fully neutralised by the base2 such salts are termed acid salts4 ,bicarbonate of soda is one of these acid salts1 but so feeble is carbonic acid in its acid properties and practical evidences1 that we shall see both monocarbonate or neutral carbonate of soda and bicarbonate or acid carbonate of soda show evidences of1 or1 as chemists say1 react with alkalinity towards litmus4 ,however1 phenolphthalein1 though reacting alkaline with monocarbonate of soda1 indicates the acidity of the bicarbonate of soda1 a thing which1 as ,i have just said1 litmus will not do4 ,we will take two jars containing solution of monocarbonate of soda1 and in the first we will put some phenolphthalein solution1 and in the second1 some litmus tincture4 ,the solution in the first jar turns rose coloured1 and in the second1 blue1 indicating in each case that the solution is alkaline4 ,if now1 however1 carbonic acid be blown into the two solutions1 that in the first jar1 containing the phenolphthalein1 becomes colourless as soon as the monocarbonate of soda is converted into bicarbonate1 and this disappearance of the rose colour indicates acidity2 the blue solution in the jar containing litmus1 on the other hand1 is not altered by blowing in carbonic acid4 ,furthermore1 if to the colourless solution containing phenolphthalein1 and which is acid towards that reagent1 a little reddened litmus is added1 this is still turned blue1 and so still indicates the presence of alkali4 ,we have1 therefore1 in bicarbonate of soda a salt which behaves as an acid to phenolphthalein and as an alkali to litmus4 ,another extremely sensitive indicator is the coal-tar dyestuff known as ,congo red2 the colour changes produced by it are exactly the inverse of those produced in the case of litmus1 that is1 it gives a blue colour with acids and a red colour with alkalis4 ,we have now learned that acids are as the antipodes to alkalis or bases1 and that the two may combine to form products which may be neutral or may have a preponderance either of acidity or of basicity--in short1 they may yield neutral1 acid1 or basic salts4 ,i must try to give you a yet clearer idea of these three classes of salts4 ,now acids in general have1 as we have seen1 what we may call a chemical appetite1 and each acid in particular has a specific chemical appetite for bases1 that is1 each acid is capable of combining with a definite quantity of an individual base4 ,the terms chemical appetite and specific chemical appetite are names ,i have coined for your present benefit1 but for which chemists would use the words affinity and valency respectively4 ,now some acids have a moderate specific appetite1 whilst others possess a large one1 and the same may be said of bases1 and thus as an example we may have mono-1 di-1 and tri-acid salts1 or mono-1 di-1 and tri-basic salts4 ,in a tri-acid salt a certain voracity of the base is indicated1 and in a tri-basic salt1 of the acid4 ,again1 with a base capable of absorbing and combining with its compound atom or molecule several compound atoms or molecules of an acid1 we have the possibility of partial saturation1 and1 perhaps1 of several degrees of it1 and also of full saturation1 which means combination to the full extent of the powers of the base in question4 ,also1 with an acid capable of1 or possessing a similar large absorptive faculty for bases1 we have possibilities of the formation of salts of various degrees of basicity1 according to the smaller or larger degree of satisfaction given to the molecule of such acid by the addition of a base4 ,we will now take as a simple case that of hydrochloric acid 7spirits of salt71 which is a monobasic acid1 that is1 its molecule is capable of combining with only one molecule of a monoacid base4 ,hydrochloric acid may be written1 as its name would indicate1 ,h,cl1 and an addition even of excess of such a base as caustic soda 7written ,na,o,h7 would only yield what is known as common salt or chloride of sodium 7,na,cl71 in which the metal sodium 7,na7 has replaced the hydrogen 7,h7 of the hydrochloric acid4 ,now chloride of sodium when dissolved in water will turn litmus neither blue nor red2 it is therefore neutral4 ,such simple1 neutral1 monobasic salts are mostly very stable4 ,by stable we mean they possess considerable resistance to agencies1 that1 in the case of other salts1 effect decompositions of those salts4 ,such other salts which are decomposed more or less readily are termed unstable1 but the terms are of course only comparative4 ,now let us consider a di- or bi-basic acid4 ,such an one is vitriol or sulphuric acid 7,h#b,,so#d74 ,the hydrogen atoms are in this case an index of the basicity of the acid1 and accordingly the fully saturated sodium salt is ,na#b,,so#d or neutral1 or better normal1 sulphate of soda4 ,in like manner the fully saturated salt of the dibasic acid1 carbonic acid 7,h#b;,,co#c71 is ,na#b;,,co#c1 ordinary or normal carbonate of soda4 ,but we must observe that with these dibasic acids it is possible1 by adding insufficient alkali to completely saturate them1 to obtain salts in which only one hydrogen atom of the acid is replaced by the metal of the base4 ,thus sulphuric and carbonic acids yield ,na,h,s,o#d1 acid sulphate or bisulphate of soda1 and ,na,h,c,o#c1 bicarbonate of soda1 respectively4 ,an example of a tribasic acid is phosphoric acid1 ,h#c,,po#d1 and here we may have three different classes of salts of three various degrees of basicity or base-saturation4 ,we may have the first step of basicity due to combination with soda1 ,na,h#b,,po#d1 or monosodium phosphate1 the second step1 ,na#c;,,hpo#d1 or disodium phosphate1 and the third1 and final step1 ,na#c,,po#d1 or trisodium phosphate4 ,now let us turn to the varying degrees of acidity1 or rather the proportions of acid radicals in salts1 due to the varying appetites or combining powers of bases4 ,sodium only forms simple monoacid salts1 as sodium chloride 7,na,cl71 sodium sulphate 7,na#b,,so#d72 calcium forms diacid salts1 e4g4 calcium chloride 7,ca,cl#b72 and aluminium and iron1 triacid salts1 for example1 aluminium sulphate ,al#b7,,so#d7c and iron 7ferric7 sulphate ,fe#b7,,so#d7c4 ,now in these triacid salts we can remove some of the acid groups and substitute the elements of water1 ,,oh1 or hydroxyl1 as it is called1 for them4 ,such salts1 then1 only partly saturated with acid1 are termed basic salts4 ,thus we have ,al#b7,,oh7#b7,,so#d7b1 ,al#b7,,oh7#d,,so#d1 as well as ,al#b7,,so#d7c1 and we can get these basic salts by treating the normal sulphate ,al#b7,,so#d7c with sufficient caustic soda to remove the necessary quantities of sulphuric acid4 ,now it is a curious thing that of these aluminium sulphates the fully saturated one1 ,al#b7,,so#d7c1 is the most stable1 for even on long boiling of its solution in water it suffers no change1 but the more basic is the sulphate the less stable it becomes1 and so the more easily it decomposes on heating or boiling its solution1 giving a deposit or precipitate of a still more basic sulphate1 or of hydrated alumina itself1 ,al#b7,,oh7#f1 until we arrive at the salt ,al#b7,,so#d7b7,,oh7#b1 which is quite unstable on boiling2 ,al#b7,,so#d77,,oh7#d would be more unstable still4 ,this behaviour may be easily shown experimentally4 ,we will dissolve some cake alum or normal sulphate of alumina1 ,al#b7,,so#d7c1 in water1 and boil some of the solution4 ,no deposit or precipitate is produced2 the salt is stable4 ,to another portion of the solution we will add some caustic soda1 ,na,o,h1 in order to rob the normal sulphate of alumina of some of its sulphuric acid4 ,this makes the sulphate of alumina basic1 and the more basic1 the more caustic soda is added1 the sodium 7,na7 of the caustic soda combining with the ,,so#d of the sulphate of alumina to form sulphate of soda 7,na#b,,so#d71 whilst the hydroxyl 7,,oh7 of the caustic soda takes the position previously occupied by the ,,so#d4 ,but this increase of basicity also means decrease of stability1 for on boiling the solution1 which now contains a basic sulphate of alumina1 a precipitate is formed1 a result which also follows if more caustic soda is added1 production of still more basic salts or of hydrated alumina1 ,al#b7,,oh7#f1 taking place in either case4 ,mordanting or ,fixing ,acid 7,phenolic7 ,colours4--,but what has all this to do with mordanting8 is possibly now the inquiry4 ,so much as this1 that only such unstable salts as ,i have just described1 which decompose and yield precipitates by the action on them of alkalis1 heat1 the textile fibres themselves1 or other agencies1 are suitable to act as true mordants4 ,hence1 generally1 the sources or root substances of the best and most efficient mordants are the metals of high specific appetite or valency4 ,i think we have now got a clue to the principle of mordants and also to the importance of a sound chemical knowledge in dealing most effectively with them1 and ,i may tell you that the man who did most to elucidate the theory of mordanting is not a practical man in the general sense of the term1 but a man of the highest scientific attainments and standing1 namely1 ,professor ,liechti1 who1 with his colleague ,professor ,suida1 did probably more than any other man to clear up much that heretofore was cloudy in this region4 ,we have seen that with aluminium sulphate1 basic salts are precipitated1 i4e4 salts with such a predominance of appetite for acids1 or such quasi-acids as phenolic substances1 that if such bodies were present they would combine with the basic parts of those precipitated salts as soon as the latter were formed1 and all would be precipitated together as one complex compound4 ,just such peculiar quasi-acid1 or phenolic substances are ,alizarin1 and most of the natural adjective dyestuffs1 the colouring principles of logwood1 cochineal1 ,persian berries1 etc4 ,hence these substances will be combined and carried down with such precipitated basic salts4 ,the complex compounds thus produced are coloured substances known as lakes4 ,for example1 if ,i take a solution containing basic sulphate of alumina1 prepared as ,i have already described1 and add to some ,alizarin1 and then heat the mixture1 ,i shall get a red lake of ,alizarin and alumina precipitated4 ,if ,i had taken sulphate of iron instead of sulphate of alumina1 and proceeded in a similar manner1 and added ,alizarin1 ,i should have obtained a dark purple lake4 ,now if you imagine these reactions going on in a single fibre of a textile material1 you have grasped the theory and purpose of mordanting4 ,the textile fabric is drawn through the alumina solution to fill the pores and tubes of the fabric2 it is then passed through a weak alkaline bath to basify or render basic the aluminium salt in the pores2 and then it is finally carried into the dye-bath and heated there1 in order to precipitate the colour lake in the fibre4 ,the method usually employed to mordant woollen fabrics consists in boiling them with weak solutions of the metallic salts used as mordants1 often with the addition of acid salts1 cream of tartar1 and the like4 ,a partial decomposition of the metallic salts ensues1 and it is induced by several conditions3 7#a7 ,the dilution of the liquid2 7#b7 the heating of the solution2 7#c7 the presence of the fibre1 which itself tends to cause the breaking up of the metallic salts into less soluble basic ones4 ,thus it is not really necessary to use basic aluminium sulphate for mordanting wool1 since the latter itself decomposes the normal or neutral sulphate of alumina on heating1 an insoluble basic sulphate being precipitated in the fibres of the wool4 7#d7 ,the presence of other added substances1 as cream of tartar1 etc4 ,the best alumina mordant is probably the acetate of alumina 7red liquor71 and the best iron mordant1 probably also the acetate 7iron liquor7 7see preceding lecture71 because the acetic acid is so harmless to the fibre1 and is easily driven off on steaming1 etc4 ,a further reason is that from the solution of acetate of iron or alumina1 basic acetates are very easily precipitated on heating1 and are thus readily deposited in the fibre4 ,mordanting and ,fixing ,basic ,colours4--,now let us ask ourselves a very important question4 ,suppose we have a colour or dyestuff1 such as ,magenta1 which is of a basic character1 and not of an acid or phenolic character like the colours ,alizarin1 ,hmatein 7logwood71 or carminic acid 7cochineal71 and we wish to fix this basic dyestuff on the tissue4 ,can we then use red liquor 7acetate of alumina71 acetate of iron1 copperas1 etc48 ,the answer is1 ,no2 for such a process would be like trying to combine base with base1 instead of base with acid1 in order to form a salt4 ,combination1 and so precipitation1 would not take place2 no lake would be formed4 ,we must seek for an acid or acid body to use as mordant for our basic colour1 and an acid or acid body that will form an insoluble precipitate or colour-lake with the dyestuff4 ,an acid much used1 and very valuable for this purpose1 is tannic acid4 ,the tannate of rosaniline 7colour principle of ,magenta7 is a tolerably insoluble lake1 which can be precipitated by ,magenta from a solution of tannate of soda1 the ,magenta being capable of displacing the soda4 ,but tannic acid1 alone1 does not form very fast lakes with ,magenta and the other basic dyestuffs1 and so a means of rendering these lakes more insoluble is needed4 ,it is found that tannic acid and tartar emetic 7a tartrate of antimony and potash7 yield a very insoluble compound1 a tannate of antimony4 ,perchloride of tin1 in a similar manner1 yields insoluble tannate of tin with tannic acid4 ,these insoluble compounds1 however1 have sufficient acid-affinity left in the combined tannic acid to unite also with the basic aniline colours1 forming very fast or insoluble colour lakes4 ,this principle is extensively used in practice to fix basic aniline colours1 especially on cotton4 ,we should first soak the piece of cotton in a solution of tannic acid1 and then pass it into a solution1 say1 of tartar emetic1 when the tannic acid will be firmly fixed1 as tannate of antimony1 on the cotton4 ,we then dip the mordanted piece of cotton into the colour bath1 containing1 for instance1 ,magenta1 and it is dyed a fine red1 composed of a tannate of antimony and ,magenta4 ,you now see1 no doubt1 the necessity of sharply discriminating between two classes of colouring matters1 which we may term colour acids and colour bases respectively4 ,there are but few acids that act like tannic acid in fixing basic aniline dyestuffs1 but oleic acid and other fatty acids are of the number4 ,a curious question might now be asked1 namely3 ,could the acid colour ,alizarin1 if fixed on cotton cloth1 combine with a basic aniline colour1 e4g4 ,aniline ,violet1 and act as a mordant for it1 thus fixing it8 ,the answer is1 ,certainly2 and thus an ,alizarin ,purple would be produced1 whilst if ,magenta were used in place of ,aniline ,violet1 an ,alizarin ,red of a crimson tone would result4 ,chrome ,mordanting of ,wool and ,fur4--,in studying this subject ,i would recommend a careful perusal of the chapter on ,mordants in ,j4,j4 ,hummel's book1 entitled ,the ,dyeing of ,textile ,fabrics1 and pages #ccg to #cdj of ,bowman's work on ,the ,wool-,fibre4 ,in the treatment of wool or fur with bichrome 7potassium bichromate7 we start with an acid salt1 a bichromate 7,k#b;,cr#b,o#g7 and a strong oxidising agent1 and we finish with a basic substance1 namely1 oxide of chromium1 in the fibres of the wool or fur4 ,if we desire to utilise the whole of the chromic acid in our mordanting liquor1 we must add to it some sulphuric acid to set free the chromic acid from the potassium with which it is combined4 ,bichromate of potash with sulphuric acid gives sulphate of potash and chromic acid4 ,the question of the proper exhaustion of bichromate baths is an important economic one4 ,now we must remember that this chromic acid 7,cr,o#c7 oxidises our wool or fur1 and must oxidise it before it can of itself act as a mordant by being reduced in the process to hydrated chromic oxide1 ,cr#b,o#c #c ,h#b,o4 #b ,cr,o#c 7chromic acid7 ,cr#b,o#c 7chromic oxide7 ,o#c 7oxygen74 ,it is this hydrated chromic oxide in the fibre that yields with the ,hmatein of the logwood your logwood black dye4 ,mr4 ,jarmain finds that it is not safe to use more than #c per cent4 7of the weight of the wool7 of bichromate2 if #d per cent4 be used1 the colour becomes impaired1 whilst if #ab per cent4 be employed1 the wool cannot be dyed at all with logwood1 the phenomenon known as over-chroming being the result of such excessive treatment4 ,i think there is no doubt1 as ,professor ,hummel says1 that the colouring matter is oxidised and destroyed in such over-chroming1 but ,i also think that there can be no doubt that the wool itself is also greatly injured and incapacitated for taking up colour4 ,now the use of certain coal-tar black dyes in place of logwood obviates this use of bichrome1 and thus the heavy stress on the fibre in mordanting with it4 ,it also effects economy in avoiding the use of bichrome1 as well as of copper salts2 but even thus1 of course1 other problems have to be solved before it can be finally decided which is best4 ,,lecture ,,ix ,,dyestuffs ,,and ,,colours ,classification4--,in classifying the different dyestuffs and colouring matters it is1 of course1 necessary to consider first the properties of those colouring matters generally1 and secondly the particular reason for making such classification4 ,the scientific chemist1 for example1 would classify them according to theoretical considerations1 as members of certain typical groups2 the representative of medical science or hygiene would naturally classify them as poisonous and non-poisonous bodies2 whilst the dyer will as naturally seek to arrange them according to their behaviour when applied to textile fabrics4 ,but this behaviour on applying to textile fibres1 if varied in character according to the chemical nature of the colouring matter1 as well as the chemical and physical nature of the fabric--and it is so varied--will make such classification1 if it is to be thorough-going1 not a very simple matter4 ,i may tell you that it is not a simple matter1 and1 moreover1 the best classification and arrangement is that one which depends both on the action of the dyes on the fibres1 and also on the intrinsic chemical character of the dyestuffs themselves4 ,since the higher branches of organic chemistry are involved in the consideration of the structure and dispositions1 and consequently more or less of the properties of these dyes1 you will readily comprehend that the thorough appreciation and use of that highest and best method of classification1 particularly in the case of the coal-tar dyes1 will be1 more or less1 a sealed book except to the student of organic chemistry4 ,but it may be asked1 ,how does that highest and best method of classifying the dyestuffs affect the users1 the dyers1 in their processes8 ,in reply1 ,i would say1 ,i believe that the dyer who so understands the chemical principles involved in the processes he carries out1 and in the best methods of classifying the dyes as chemical substances1 so as to be able to act independently of the prescriptions and recipes given him by the dye manufacturers1 and so be master of his own position1 will1 ceteris paribus1 be the most economical and successful dyer4 ,many manufacturers of dyestuffs have said the very same thing to me1 but1 independently of this1 ,i know it1 and can prove it with the greatest ease4 ,let me now1 by means of an experiment or two1 prove to you that at least some classification is necessary to begin with4 ,so different and varied are the substances used as colouring matters by the dyer1 both as regards their chemical and physical properties1 that they even act differently towards the same fibre4 ,i will take four pieces of cotton fabric2 three of them are simple white cotton1 whilst the fourth cotton piece has had certain metallic salts mixed with thickening substances like gum1 printed on it in the form of a pattern1 which at present cannot readily be discerned4 ,we will now observe and note the different action on these pieces of cotton--7i47 of a ,turmeric bath1 7ii47 a ,magenta bath1 and 7iii47 a madder or ,alizarin bath4 ,the ,turmeric dyes the cotton a fast yellow1 the ,magenta only stains the cotton crimson1 and on washing with water alone1 almost every trace of colour is removed again2 the madder1 however1 stains the cotton with no presentable shade of colour at all1 produces a brownish-yellow stain1 removed at once by a wash in water4 ,but let us take the printed piece of cotton and dye that in the ,alizarin bath1 and then we shall discover the conditions for producing colours with such a dyestuff as madder or ,alizarin4 ,different coloured stripes are produced1 and the colours are conditioned by the kind of metallic salts used4 ,evidently the way in which1 the turmeric dyes the cotton is different from that in which the madder dyes it4 ,the first is a yellow dyestuff1 but it would be hard to assign any one shade or tint to ,alizarin as a dyestuff4 ,in fact ,alizarin 7the principle of madder7 is of itself not a dye1 but it forms with each of several metals a differently coloured compound2 and thus the metallic salt in the fabric is actually converted into a coloured compound1 and the fabric is dyed or printed4 ,the case is just the same with logwood black dyeing3 without the presence of iron 7copperas1 etc471 sulphate of copper 7bluestone71 or bichrome1 you would get no black at all4 ,we will now try similar experiments with woollen fabrics1 taking three simple pieces of flannel1 and also two pieces1 the one having been first treated with a hot solution of alum and cream of tartar1 and the other with copperas or sulphate of iron solution1 and then washed4 ,turmeric dyes the first yellow1 like it did the cotton4 ,magenta1 however1 permanently dyes the woollen as it did not the cotton4 ,alizarin only stains the untreated woollen1 whilst the piece treated with alumina is dyed red1 and that with iron1 purple4 ,if1 however1 the pieces treated with iron and alumina had been dyed in the ,magenta solution1 only one colour would have been the result1 and that a ,magenta-red in each case4 ,here we have1 as proved by our experiments1 two distinct classes of colouring matters4 ,the one class comprises those which are of themselves the actual colour4 ,the colour is fully developed in them1 and to dye a fabric they only require fixing in their unchanged state upon that fabric4 ,such dyes are termed monogenetic1 because they can only generate or yield different shades of but one colour4 ,indigo is such a dye1 and so are ,magenta1 ,aniline ,black1 ,aniline ,violet1 picric acid1 ,ultramarine ,blue1 and so on4 ,ultramarine is not1 it is true1 confined to blue2 you can get ,ultramarine ,green1 and even rose-coloured ,ultramarine2 but still1 in the hands of the dyer1 each shade remains as it came from the colour-maker1 and so ,ultramarine is a monogenetic colour4 ,monogenetic means capable of generating one4 ,turning to the other class1 which comprises1 as we have shown1 ,alizarin1 and1 besides1 the colouring principle of logwood 7,hmatein71 ,gallein1 and ,cochineal1 etc41 we have bodies usually possessed of some colour1 it is true1 but such colour is of no consequence1 and1 indeed1 is of no use to dyers4 ,these bodies require a special treatment to bring out or develop the colours1 for there may be several that each is capable of yielding4 ,we may consider them as colour-giving principles1 and so we term them polygenetic colours4 ,polygenetic means capable of generating several or many4 ,in the various colours and dyes we have all phases1 and the monogenetic shades almost imperceptibly into the polygenetic4 ,the mode of application of the two classes of colours is1 of course1 in each case quite essentially different1 for in the case of the monogenetic class the idea is mainly either to dye at once and directly upon1 the unprepared fibre1 or having subjected the fabric to a previous preparation with a metallic or other solution1 to fix directly the one colour on that fabric1 on which1 without such preparation1 it would be loose4 ,in the case of the polygenetic class1 the idea is necessarily twofold4 ,the dyeing materials are not colours1 only colour generators4 ,hence in all cases the fabric must be prepared with the twofold purpose--first1 of using a metallic or other agent1 capable of yielding1 with the dye material1 the desired colour2 and secondly1 of yielding it on the fibre in an insoluble and permanent form4 ,now1 though ,i have gone so far into this mode of classification1 because it does afford some information and light1 yet ,i can go no farther without getting into a territory that presupposes a knowledge and acquaintance with the chemical structure of the colouring matters as organic substances1 which would be1 at present1 beyond us4 ,i shall now turn to another mode of classification1 which1 if not so far-reaching as the other1 is at least an exceedingly useful one4 ,the two methods may be combined to a considerable extent4 ,by the latter plan the colours may be conveniently divided into three groups3 ,i41 substantive colours2 ,,ii41 adjective colours2 ,,iii41 mineral and pigment colours4 ,substantive ,dyestuffs4--,the substantive colours fix themselves readily and directly on animal fibres and substances1 but only a few amongst them will dye vegetable fibres like cotton and linen directly4 ,almost all substantive colours may1 however1 be fixed on cotton and linen by first preparing or mordanting those vegetable fibres4 ,silk1 wool1 fur1 etc41 act like fibre and mordant together1 for they absorb and fix the substantive colours firmly4 ,in our experiments we saw that turmeric is one of the few substantive colours fixing itself on both cotton and wool1 without any aid from a mordant or fixing agent4 ,magenta was also a substantive colour1 but ,alizarin was certainly not one of this class4 ,adjective ,dyestuffs4--,some of these substances are definitely coloured bodies1 but in some of them the colour is of no consequence or value1 and is quite different and distinct from the colour eventually formed on the fibre1 which colour only appears in conjunction with a special mordant2 but1 again1 some of them are not coloured1 and would not colour the fibre directly at all1 only in conjunction with some mordant4 ,all the polygenetic colours are1 of course1 comprised in this class1 for example ,alizarin and logwood 7,hmatein71 whilst such monogenetic colours as annatto and turmeric are substantive1 for they will fix themselves without a mordant on cotton and wool4 ,the adjective colours can be conveniently subdivided into--7a7 those existing in nature1 as logwood 7,hmatein7 and ,cochineal2 7b7 those artificially formed from coal-tar products1 as ,alizarin 7madder71 ,gallein1 etc4 ,mineral and ,pigment ,dyestuffs4--,these colours are insoluble in water and alcohol4 ,they are either fixed on the fibre by mechanical means or by precipitation4 ,for example1 you use blacklead or plumbago to colour or darken your hats1 and you work on this pigment colour by mechanical means4 ,i will show you by experiment how to fix a coloured insoluble pigment in the fibre4 ,i take a solution of acetate of lead 7sugar of lead71 and to it ,i add some solution of bichrome 7potassium bichromate74 ,acetate of lead 7soluble in water7 with bichromate of potash 7also soluble in water7 yields1 on mixing the two1 acetate of potash 7soluble in water71 and chromate of lead1 or chrome yellow 7insoluble in water71 and which is consequently precipitated or deposited4 ,now suppose ,i boil some of that chrome-yellow precipitate with lime-water1 ,i convert that chrome yellow into chrome orange4 ,this1 you see1 takes place without any reference to textile fibres4 ,i will now work a piece of cotton in a lead solution1 so that the little tubes of the cotton fibre shall be filled with it just as the larger glass tube or vessel was filled in the first experiment4 ,i next squeeze and wash the piece1 so as to remove extraneous solution of lead1 just as if ,i had filled my glass tube by roughly dipping it bodily into the lead solution1 and then washed and cleansed the outside of that tube4 ,then ,i place the fabric in a warm solution of bichromate of potash 7bichrome71 when it becomes dyed a chrome yellow1 for just as chromate of lead is precipitated in the glass tube1 so it is now precipitated in the little tubes of the cotton fibre 7see ,lecture ,i474 ,let us see if we can now change our chrome yellow to chrome orange1 just as we did in the glass vessel by boiling in lime-water4 ,i place the yellow fabric in boiling lime-water1 when it is coloured or dyed orange4 ,in each little tubular cotton fibre the same change goes on as went on in the glass vessel1 and as the tube or glass vessel looks orange1 so does the fabric1 because the cotton fibres or tubes are filled with the orange chromium compound4 ,you see this is quite a different process of pigment colouring from that of rubbing or working a colour mechanically on to the fibre4 ,let us now turn to the substantive colours 7,group ,i471 and see if we can further sub-divide this large group for the sake of convenience4 ,we can divide the group into two--7a7 such colours as exist ready formed in nature1 and chiefly occur in plants1 of which the following are the most important3 indigo1 archil or orchil1 safflower1 turmeric1 and annatto2 7b7 the very large sub-group of the artificial or coal-tar colours4 ,we will briefly consider now the dyestuffs mentioned in ,group 7a74 ,natural ,substantive ,colours4--,indigo1 one of the most valuable dyes1 is the product of a large number of plants1 the most important being different species of indigofera1 which belong to the pea family4 ,none of the plants 7of which indigofera tinctoria is the chief7 contain the colouring matter in the free state1 ready-made1 so to say1 but only as a peculiar colourless compound called indican1 first discovered by ,edward ,schunck4 ,when this body is treated with dilute mineral acids it splits up into ,indigo ,blue and a kind of sugar4 ,but so easily is this change brought about that if the leaf of the plant be only bruised1 the decomposition ensues1 and a blue mark is produced through separation of the ,indigo ,blue4 ,the possibility of dyeing with ,indigo so readily and easily is due to the fact that ,indigo ,blue absorbs hydrogen from bodies that will yield it1 and becomes1 as we say1 reduced to a body without colour1 called ,indigo ,white1 a body richer in hydrogen than ,indigo ,blue1 and a body that is soluble4 ,if this white body 7,indigo ,white7 be exposed to the air1 the oxygen of the air undoes what the hydrogen did1 and oxidises that ,indigo ,white to insoluble ,indigo ,blue4 ,textile fabrics dipped in such reduced indigo solutions1 and afterwards exposed to the air1 become blue through deposit in the fibres of the insoluble ,indigo ,blue1 and are so dyed4 ,this is called the indigo-vat method4 ,we can reduce this indigo so as to prepare the indigo-vat by simply mixing ,indigo ,blue1 copperas 7ferrous sulphate7 solution1 and milk of lime in a closely-stoppered bottle with water1 and letting the mixture stand4 ,the clear liquor only is used4 ,a piece of cotton dipped in it1 and exposed to the air1 quickly turns blue by absorbing oxygen1 and is thus dyed4 ,the best proportions for the indigo-vat are1 for cloth dyeing1 #djjj parts of water1 #dj of indigo1 #fj to #hj of copperas crystals1 and #ej to #ajj of dry slaked lime4 ,the usual plan is to put in the water first1 then add the indigo and copperas1 which should be dissolved first1 and finally to add the milk of lime1 stirring all the time4 ,artificial indigo has been made from coal-tar products4 ,the raw material is a coal-tar naphtha called toluene or toluol1 which is also the raw material for saccharin1 a sweetening agent made from coal-tar4 ,this artificial indigo is proving a formidable rival to the natural product4 ,orchil paste1 orchil extract1 and cudbear are obtained by exposing the plants 7species of lichens7 containing the colouring principle1 called ,orcin1 itself a colourless substance1 to the joint action of ammonia and air1 when the oxygen of the air changes that orcin by oxidising it into ,orcin1 which is the true red colouring matter contained in the preparations named4 ,the lichens thus treated acquire gradually a deep purple colour1 and form the products called cudbear4 ,this dye works best in a neutral bath1 but it will do what not many dyes will1 namely1 dye in either a slightly alkaline or slightly acid bath as well4 ,orchil is not applicable in cotton dyeing4 ,being a substantive colour no mordants are needed in dyeing silk and wool with it4 ,the colour produced on wool and silk is a bright magenta-red with bluish shade4 ,litmus is also obtained from the same lichens as yield orchil4 ,it is not used in dyeing1 and is a violet-blue colouring matter when neither acid nor alkaline1 but neutral as it is termed4 ,it turns red with only a trace of acid1 and blue with the least trace of alkali1 and so forms a very delicate reagent when pieces of paper are soaked with it1 and dipped into the liquids to be tested4 ,safflower3 ,this vegetable dyeing material1 for producing pink colours on cotton without the aid of a mordant1 consists of the petals of the flower of carthamus tinctorius4 ,it contains a principle termed ,carthamin or carthamic acid1 which can be separated by exhausting safflower with cold acidulated water 7sulphuric acid7 to dissolve out a yellow colouring matter which is useless4 ,the residue after washing free from acid is treated with a dilute solution of soda crystals1 and the liquid is then precipitated by an acid4 ,a red precipitate is obtained1 which fixes itself directly on cotton thread immersed in the liquid1 and dyes it a delicate rose pink1 which is1 unfortunately1 very fugitive4 ,silk can be dyed like cotton4 ,the colour is not fast against light4 ,turmeric is the root portion of a plant called curcuma tinctoria1 that grows in ,southern ,asia4 ,the principle forming the colouring matter is ,curcumin4 ,it is insoluble in cold water1 not much soluble in hot1 but easily soluble in alcohol4 ,from the latter solution it separates in brilliant yellow crystals4 ,although the colour it yields is very fugitive1 the wool and silk dyers still use it for producing especially olives1 browns1 and similar compound shades4 ,it produces on cotton and wool a bright yellow colour without the aid of any mordant4 ,to show you how easily dyeing with turmeric is effected1 ,i will warm some powdered turmeric root in a flask with alcohol1 and add the extract to a vessel of water warmed to about #adj ,f4 7#fj ,c471 and then dip a piece of cotton in and stir it about1 when it will soon be permanently dyed a fine bright yellow4 ,a piece of wool similarly worked in the bath is also dyed4 ,however1 the unfortunate circumstance is that this colour is fast neither to light nor alkalis4 ,contact with soap and water1 even1 turns the yellow-dyed cotton1 reddish-brown4 ,annatto is a colouring principle obtained from the pulpy matter enclosing the seeds of the fruit of a tree1 the ,bixa orellana1 growing in ,central and ,southern ,america4 ,the red or orange colour it yields is fugitive1 and so its use is limited1 being chiefly confined to silk dyeing4 ,the yellow compound it contains is called ,orellin1 and it also contains an orange compound called ,bixin1 which is insoluble in water1 but readily soluble in alkalis and in alcohol with a deep yellow colour4 ,to dye cotton with it1 a solution is made of the colour in a boiling solution of carbonate of soda4 ,the cotton is worked in the diluted alkaline solution whilst hot4 ,by passing the dyed cotton through water acidulated with a little vitriol or alum1 a redder tint is assumed4 ,for wool and silk1 pale shades are dyed at #ajf ,f4 7#ej ,c47 with the addition of soap to the bath1 dark shades at #bjj to #bab ,f4 7#hj to #ajj ,c474 ,,lecture ,x ,,dyestuffs ,,and ,,colours--,continued ,artificial ,substantive ,dyestuffs4--,you may remember that in the last lecture we divided the colouring matters as follows3 ,i4 ,substantive colours1 fixing themselves directly on animal fibres without a mordant1 only a few of them doing this1 however1 on vegetable fibres1 like cotton4 ,we sub-divided them further as--7a7 those occurring in nature1 and 7b7 those prepared artificially1 and chiefly1 but not entirely1 the coal-tar colouring matters4 ,,ii4 ,adjective colours1 fixing themselves only in conjunction with a mordant or mordants on animal or vegetable fibres1 and including all the polygenetic colours4 ,,iii4 ,mineral or pigment colours4 ,i described experiments to illustrate what we mean by monogenetic and polygenetic colours1 and indicating that the monogenetic colours are mainly included in the group of substantive colours1 whilst the polygenetic colours are mainly included in the adjective colours4 ,but ,i described also an illustration of ,group ,,iii41 the mineral or pigment colours1 by which we may argue that chromate of lead is a polygenetic mineral colour1 for1 according to the treatment1 we were able to obtain either chrome yellow 7neutral lead chromate7 or chrome orange 7basic lead chromate74 ,i also said there was a kind of borderland whichever mode of classification be adopted4 ,thus1 for example1 there are colours that are fixed on the fibre either directly like indigo1 and so are substantive1 or they may be1 and generally are1 applied with a mordant like the adjective and polygenetic colours2 examples of these are ,coerulein1 ,alizarin ,blue1 and a few more4 ,we have now before us a vast territory1 namely1 that of the b group of substantive colours1 or1 the largest proportion1 indeed almost all of those prepared from coal-tar sources2 ,alizarin1 also prepared from coal-tar1 belongs to the adjective colours4 ,with regard to the source of these coal-tar colours1 the word coal-tar1 ,i was going to say1 speaks volumes1 for the destructive and dry distillation of coal in gas retorts at the highest temperatures to yield illuminating gas1 also yields us tar4 ,but1 coal distilled at lower temperatures1 as well as shale1 as in ,scotland1 will yield tar1 but tar of another kind1 from which colour-generating substances cannot be obtained practically1 but instead1 paraffin oil and paraffin wax for making candles1 etc4 ,coal-tar contains a very large number of different substances1 but only a few of them can be extracted profitably for colour-making4 ,all the useful sources of colours and dyes from coal-tar are simply compounds of carbon and hydrogen--hydrocarbons1 as they are called1 with the exception of one1 namely1 phenol1 or carbolic acid4 ,i am not speaking here of those coal-tar constituents useful for making dyes1 but of those actually extracted from coal-tar for that purpose1 i4e4 extracted to profit4 ,for example1 aniline is contained in coal-tar1 but if we depended on the aniline contained ready made in coal-tar for our aniline dyes1 the prices of these dyes would place them beyond our reach1 would place them amongst diamonds and precious stones in rarity and cost1 so difficult is it to extract the small quantity of aniline from coal-tar4 ,the valuable constituents actually extracted are then these3 benzene1 toluene1 xylene1 naphthalene1 anthracene1 and phenol or carbolic acid4 ,one ton of ,lancashire coal1 when distilled in gas retorts1 yields about #ab gallons of coal-tar4 ,let us now learn what those #ab gallons of tar will give us in the shape of hydrocarbons and carbolic acid1 mentioned as extracted profitably from tar4 ,this is shown very clearly in the following table 7,table ,a74 ,the #ab gallons of tar yield #a-a_/aj lb4 of benzene1 #i_/aj lb4 of toluene1 #a-a_/b lb4 of carbolic acid1 between #a_/aj and #b_/aj lb4 of xylene1 #f-a_/b lb4 of naphthalene1 and #a_/b lb4 of anthracene1 whilst the quantity of pitch left behind is #fi-a_/b lb4 ,but our table shows us more2 it indicates to us what the steps are from each raw material to each colouring matter1 as well as showing us each colouring matter4 ,we see here that our benzene yields us an equal weight of aniline1 and the toluene 7#i_/aj lb47 about #c_/d lb4 of toluidine1 the mixture giving1 on oxidation1 between #a_/b and #c_/d lb of ,magenta4 ,from carbolic acid are obtained both ,aurin and picric acid1 and here is the actual quantity of ,aurin obtainable 7#a-a_/d lb474 ,from naphthalene1 either naphthylamine 7a body like aniline7 or naphthol 7resembling phenol7 may be prepared4 ,the amounts obtainable you see in the table4 ,there are two varieties of naphthol1 called alpha- and beta-naphthol1 but only one phenol1 namely1 carbolic acid4 ,naphthol ,yellow is of course a naphthol colour1 whilst ,vermilline ,scarlet is a dye containing both naphthylamine and naphthol4 ,you see the quantities of these dyes1 namely #g lb4 of ,scarlet and #i-a_/b lb4 of the ,naphthol ,yellow4 ,the amount of pure anthracene obtained is #a_/b lb4 ,this pure anthracene exhibits the phenomenon of fluorescence1 that is1 it not only looks white1 but when the light falls on it1 it seems to reflect a delicate violet or blue light4 ,our table shows us that from the #ab gallons of tar from #a ton of coal we may gain #b-a_/d lb4 of #bj per cent4 ,alizarin paste4 ,chemically pure ,alizarin crystallises in bright-red needles2 it is the colouring principle of madder1 and also of ,alizarin paste4 ,but the most wonderful thing about substantive coal-tar colours is their immense tinctorial power1 i4e4 the very little quantity of each required compared with the immense superficies of cloth it will dye to a full shade4 ,,table ,a4#b ---------------------------------------- --------------------------------------- ,,twelve ,,gallons ,,of ,,gas-,,tar 7,,average ,,of ,,manchester ,,and ,,salford ,,tar7 ,,yield3-- ---------------------------------------- ------------------------------ ,benzene4 ,toluene4 ,p ,solvent ,h ,n ,naphthalene4 ,c ,h ,a ,p h ,naphtha e a r e n i e for a p e a t t n ,india v h o v h c o rubber1 y t s y r h l containing h o a 4 4 the three a t ,o c ,xylenes4 4 e i e 4 l n 4 e4 ---------------------------------------- -------------------------------- #aaj lb4#jij lb4#ae #bdd lb41 #bdjfcj lb4 #ag #ad #jdf lb4#fif #aaj lb4 #jgg lb4 lb4 yielding lb4 #ebe lb4 of lb4lb4 #bbe lb4 of of #ab #jab lb4 alpha- lb4 of ,aniline ,toluidinelb4 ofof ,xylene ,naphthylamine ,alizarin ,aurin4 #jjg lb4 #gaa lb4 of 7#bj74 of ,vermilline _/ ,xylidine ,scarlet #jfbc lb of ,,rrr2 or #dge ,magenta4 lb4 of alpha- or #aaj or beta- lb4 of ,naphthol ,aniline #iej lb4 of yields ,naphthol #abc lb4 ,yellow of ,methyl ,violet4 ---------------------------------------- ------------------------------ ,footnote #b3 ,this table was compiled by ,mr4 ,ivan ,levinstein1 of ,manchester4 ,the next table 7see ,table ,b7 shows you the dyeing power of the colouring matters derived from #a ton of ,lancashire coal1 which will astonish any thoughtful mind1 for the ,magenta will dye #ejj yards of flannel1 the ,aurin #abj yards1 the ,vermilline ,scarlet #befj yards1 and the ,alizarin #bee yards 7,turkey-red cotton cloth74 ,the next table 7,table ,c7 shows the latent dyeing power resident1 so to speak1 in #a lb4 of coal4 ,by a very simple experiment a little of a very fine violet dye can be made from mere traces of the materials4 ,one of the raw materials for preparing this violet dye is a substance with a long name1 which itself was prepared from aniline4 ,this substance is tetramethyldiamidobenzophenone1 and a little bit of it is placed in a small glass test-tube1 just moistened with a couple of drops of another aniline derivative called dimethylaniline1 and then two drops of a fuming liquid1 trichloride of phosphorus1 added4 ,on simply warming this mixture1 the violet dyestuff is produced in about a minute4 ,two drops of the mixture will colour a large cylinder of water a beautiful violet4 ,the remainder 7perhaps two drops more7 will dye a skein of silk a bright full shade of violet4 ,here1 then1 is a magnificent example of enormous tinctorial power4 ,i must now draw the rein1 or ,i shall simply transport you through a perfect wonderland of magic1 bright colours and apparent chemical conjuring1 without1 however1 an adequate return of solid instruction that you can carry usefully with you into every-day life and practice4 ,,table ,b4#c ---------------------------------------- --------------------------------------- ,,dyeing ,,powers ,,of ,,colours ,,from #a ,,ton ,,of ,,lancashire ,,coal4 ---------------------------------------- ---------------------------------- #jfbc lb4 of#acd lb4 of #i4e lb4 of #gaa lb4 of #ab lb4 of #bbe lb4 of ,magenta will,methyl ,naphthol ,vermilline ,aurin will ,alizarin dye #ejj ,violet will ,yellow will will dye #befj;dye #abj 7#bj7 will yards of dye #ajjj dye #chjj yards of yards of dye #bee flannel1 #bg yards of yards of flannel1 #bg flannel1 #bg yards of inches wide1flannel1 #bg flannel1 #bg inches wide1 inches wide1 ,printers' a full inches wide1inches wide1a full a full cloth a full shade4 a full a full scarlet4 orange4 ,turkey red4 violet4 yellow4 ---------------------------------------- ---------------------------------- ,,table ,c4#c ---------------------------------------- --------------------------------------- ,,dyeing ,,powers ,,of ,,colours ,,from #a ,,lb4 ,,of ,,lancashire ,,coal4 ---------------------------------------- ---------------------------------- ,methyl ,naphthol ,vermilline ,aurin ,alizarin ,magenta or ,violet4 ,yellow4 or ,scarlet4 7,orange74 7,turkey ,red7 ---------------------------------------- ---------------------------------- #h #bg #bd #bg #fa #bg #da #bg #aic #bg #d #bg inches of inches of inches of inches of inches of inches of flannel4 flannel4 flannel4 flannel4 flannel4 ,printers' cloth4 ---------------------------------------- ---------------------------------- ,footnote #c3 ,these tables were compiled by ,mr4 ,ivan ,levinstein1 of ,manchester4 ,before we go another step1 ,i must ask and answer1 therefore1 a few questions4 ,can we not get some little insight into the structure and general mode of developing the leading coal-tar colours which serve as types of whole series8 ,i will try what can be done with the little knowledge of chemistry we have so far accumulated4 ,in our earlier lectures we have learnt that water is a compound of hydrogen and oxygen1 and in its compound atom or molecule we have two atoms of hydrogen combined with one of oxygen1 symbolised as ,h#b,o4 ,we also learnt that ammonia1 or spirits of hartshorn1 is a compound of hydrogen with nitrogen1 three atoms of hydrogen being combined with one of nitrogen1 thus1 ,,nh#c4 ,an example of a hydrocarbon or compound of carbon and hydrogen1 is marsh gas 7methane7 or firedamp1 ,,ch#d4 ,nitric acid1 or aqua fortis1 is a compound of nitrogen1 oxygen1 and hydrogen1 one atom of the first to three of the second and one of the third--,,no#c;,h4 ,but this nitric acid question forces me on to a further statement1 namely1 we have in this formula or symbol1 ,,no#c;,h1 a twofold idea--first1 that of the compound as a whole1 an acid2 and secondly1 that it is formed from a substance without acid properties by the addition of water1 ,h#b,o1 or1 if we like1 ,,hoh4 ,this substance contains the root or radical of the nitric acid1 and is ,,no#b1 which has the power of replacing one of the hydrogen atoms1 or ,h1 of water1 and so we get1 instead of ,,hoh1 ,,no#b,,oh1 which is nitric acid4 ,this is chemical replacement1 and on such replacement depends our powers of building up not only colours1 but many other useful and ornamental chemical structures4 ,you have all heard the old-fashioned statement that ,nature abhors a vacuum4 ,we had a very practical example of this when in our first lecture on water ,i brought an electric spark in contact with a mixture of free oxygen and hydrogen in a glass bulb4 ,these gases at once united1 three volumes of them condensing to two volumes1 and these again to a minute particle of liquid water4 ,a vacuum was left in that delicate glass bulb whilst the pressure of the atmosphere was crushing with a force of #ae lb4 on the square inch on the outside of the bulb1 and thus a violent crash was the result of ,nature's abhorrence4 ,there is such a kind of thing1 though1 and of a more subtle sort1 which we might term a chemical vacuum1 and it is the result of what we call chemical valency1 which again might be defined as the specific chemical appetite of each substance4 ,let us now take the case of the production of an aniline colour1 and let us try to discover what aniline is1 and how formed4 ,i pointed to benzene or benzol in the table as a hydrocarbon1 ,c#f;,h#f1 which forms a principal colour-producing constituent of coal-tar4 ,if you desire to produce chemical appetite in benzene1 you must rob it of some of its hydrogen4 ,thus ,c#f;,h#e is a group that would exist only for a moment1 since it has a great appetite for ,h1 and we may say this appetite would go the length of at once absorbing either one atom of ,h 7hydrogen7 or of some similar substance or group having a similar appetite4 ,suppose1 now1 ,i place some benzene1 ,c#f;,h#f1 in a flask1 and add some nitric acid1 which1 as we said1 is ,,no#b,,oh4 ,on warming the mixture we may say a tendency springs up in that ,,oh of the nitric acid to effect union with an ,h of the ,c#f;,h#f 7benzene7 to form ,,hoh 7water71 when an appetite is at once left to the remainder1 ,c#f;,h#e--on the one hand1 and the ,,no#b--on the other1 satisfied by immediate union of these residues to form a substance ,c#f;,h#f,,no#b1 nitro-benzene or essence of mirbane1 smelling like bitter almonds4 ,this is the first step in the formation of aniline4 ,i think ,i have told you that if we treat zinc scraps with water and vitriol1 or water with potassium1 we can rob that water of its oxygen and set free the hydrogen4 ,it is1 however1 a singular fact that if we liberate a quantity of fresh hydrogen amongst our nitrobenzene ,c#f;,h#e,,no#b1 that hydrogen tends to combine1 or evinces an ungovernable appetite for the ,o#b of that ,,no#b group1 the tendency being again to form water ,h#b,o4 ,this1 of course1 leaves the residual ,c#f;,h#e,n3 group with an appetite1 and only the excess of hydrogen present to satisfy it4 ,accordingly hydrogen is taken up1 and we get ,c#f;,h#e,,nh#b formed1 which is aniline4 ,i told you that ammonia is ,,nh#c1 and now in aniline we find an ammonia derivative1 one atom of hydrogen 7,h7 being replaced by the group ,c#f;,h#e4 ,i will now describe the method of preparation of a small quantity of aniline1 in order to illustrate what ,i have tried to explain in theory4 ,benzene from coal-tar is warmed with nitric acid in a flask4 ,a strong action sets in1 and on adding water1 the nitrobenzene settles down as a heavy oil1 and the acid water can be decanted off4 ,after washing by decantation with water once or twice1 and shaking with some powdered marble to neutralise excess of acid1 the nitrobenzene is brought into contact with fresh hydrogen gas by placing amongst it1 instead of zinc1 some tin1 and instead of vitriol1 some hydrochloric acid 7spirits of salt74 ,to show you that aniline is formed1 ,i will now produce a violet colour with it1 which only aniline will give4 ,this violet colour is produced by adding a very small quantity of the aniline1 together with some bleaching powder1 to a mixture of chalk and water1 the chalk being added for the purpose of destroying acidity4 ,this aniline1 ,c#f;,h#e,,nh#b1 is a base1 and forms the foundation of all the so-called basic aniline colours4 ,if ,i have made myself clear so far1 ,i shall be contented4 ,it only remains to be said that for making ,magenta1 pure aniline will not do1 what is used being a mixture of aniline1 with an aniline a step higher1 prepared from toluene4 ,if ,i were to give you the formula of ,magenta you would be astonished at its complexity and size1 but ,i think now you will see that it is really built up of aniline derivatives4 ,methyl ,violet is a colour we have already referred to1 and its chemical structure is still more complex1 but it also is built up of aniline materials1 and so is a basic aniline colour4 ,now it is possible for the colour-maker to prepare a very fine green dye from this beautiful violet 7,methyl ,violet74 ,in fact he may convert the violet into the green colour by heating the first under pressure with a gas called methyl chloride 7,,ch#c;,cl74 ,methyl ,violet is constructed of aniline or substituted aniline groups2 the addition of ,,ch#c;,cl1 then1 gives us the ,methyl ,green4 ,but one of the misfortunes of ,methyl ,green is that if the fabric dyed with it be boiled with water1 at that temperature 7#bab ,f47 the colour is decomposed and injured1 for some of the methyl chloride in the compound is driven off4 ,in fact1 by stronger heating we may drive off all the methyl chloride and get the original ,methyl ,violet back again4 ,but we have coal-tar colours which are not basic1 but rather of the nature of acid1--a better term would be phenolic1 or of the nature of phenol or carbolic acid4 ,let us see what phenol or carbolic acid is4 ,we saw that water may be formulated ,,hoh1 and that benzene is ,c#f;,h#f4 ,well1 carbolic acid or phenol is a derivative of water1 or a derivative of benzene1 just as you like1 and it is formulated ,c#f;,h#e,,oh4 ,you can easily prove this by dropping carbolic acid or phenol down a red-hot tube filled with iron-borings4 ,the oxygen is taken up by the iron to give oxide of iron1 and benzene is obtained1 thus3 ,c#f;,h#e,,oh gives ,o and ,c#f;,h#f4 ,but there is another hydrocarbon called naphthalene1 ,c#aj;,h#h1 and this forms not one1 but two phenols4 ,as the name of the hydrocarbon is naphthalene1 however1 we call these compounds naphthols1 and one is distinguished as alpha- the other as beta-naphthol1 both of them having the formula ,c#aj;,h#g,,oh4 ,but now with respect to the colours4 ,if we treat phenol with nitric acid under proper conditions1 we get a yellow dye called picric acid1 which is trinitro-phenol ,c#f;,h#b7,,no#b7c,,oh2 you see this is no aniline dye2 it is not a basic colour1 for it would saturate1 i4e4 destroy the basicity of bases4 ,again1 by oxidising phenol with oxalic acid and vitriol1 we get a colour dyeing silk orange1 namely1 ,aurin1 ,,ho4,c,c#f;,h#d7,,oh7#c4 ,this is also an acid or phenolic dye1 as a glance at its formula will show you4 ,its compound atom bristles1 so to say1 with phenol-residues1 as some of the aniline dyes do with aniline residue-groups4 ,we come now to a peculiar but immensely important group of colours known as the azo-dyes1 and these can be basic or acid1 or of mixed kind4 ,just suppose two ammonia groups1 ,,nh#c and ,,nh#c4 ,if we rob those nitrogen atoms of their hydrogen atoms1 we should leave two unsatisfied nitrogen atoms1 atoms with an exceedingly keen appetite represented in terms of hydrogen atoms as ,n999999 and ,n9999994 ,we might suppose a group1 though of two ,n atoms partially satisfied by partial union with each other1 thus--,n3,n--4 ,now this group forms the nucleus of the azo-colours1 and if we satisfy a nitrogen at one side with an aniline1 and at the other with a phenol1 or at both ends with anilines1 and so on1 we get azo-dyes produced4 ,the number of coal-tar colours is thus very great1 and the variety also4 ,adjective ,colours4--,as regards the artificial coal-tar adjective dyestuffs1 the principal are ,alizarin and ,purpurin4 ,these are now almost entirely prepared from coal-tar anthracene1 and madder and garancine are almost things of the past4 ,vegetable adjective colours are ,brazil wood1 containing the dye-generating principle ,brasilin1 logwood1 containing ,hmatein1 and santal-wood1 camwood1 and barwood1 containing ,santalin4 ,animal adjective colours are cochineal and lac dye4 ,then of wood colours we have further3 quercitron1 ,persian berries1 fustic and the tannins or tannic acids1 comprising extracts1 barks1 fruits1 and gallnuts1 with also leaves and twigs1 as with sumac4 ,all these colours dye only with mordants1 mostly forming with certain metallic oxides or basic salts1 brightly-coloured compounds on the tissues to which they are applied4 ,,lecture ,,xi ,,dyeing ,,of ,,wool ,,and ,,fur2 ,,and ,,optical ,,properties ,,of ,,colours ,you have no doubt a tolerably vivid recollection of the illustrations given in ,lecture ,i41 showing the structure of the fibre of wool and fur4 ,we saw that the wool fibre1 of which fur might be considered a coarser quality1 possesses a peculiar1 complex1 scaly structure1 the joints reminding one of the appearance of plants of the ,equisetum family1 whilst the scaled structure resembles that of the skin of the serpent4 ,now you may easily understand that a structure like this1 if it is to be completely and uniformly permeated by a dye liquor or any other aqueous solution1 must have those scales not only well opened1 but well cleansed1 because if choked with greasy or other foreign matter impervious to or resisting water1 there can be no chance of the mordanting or dye liquids penetrating uniformly2 the resulting dye must be of a patchy nature4 ,all wool1 in its natural state1 contains a certain amount of a peculiar compound almost like a potash soap1 a kind of soft soap1 but it also contains besides1 a kind of fatty substance united with lime1 and of a more insoluble nature than the first4 ,this natural greasy matter is termed yolk or suint2 and it ought never to be thrown away1 as it sometimes is by the wool-scourers in this country1 for it contains a substance resembling a fat named cholesterin or cholesterol1 which is of great therapeutical value4 ,water alone will wash out a considerable amount of this greasy matter1 forming a kind of lather with it1 but not all4 ,as is almost invariably the case1 after death1 the matters and secretions which in life favour the growth and development of the parts1 then commence to do the opposite4 ,it is as if the timepiece not merely comes to a standstill1 but commences to run backwards4 ,this natural grease1 if it be allowed to stand in contact with the wool for some time after shearing1 instead of nourishing and preserving the fibres as it does on the living animal1 commences to ferment1 and injures them by making them hard and brittle4 ,we see1 then1 the importance of scouring wool for the removal of yolk1 as it is called1 dirt1 oil1 etc4 ,if this important operation were omitted1 or incompletely carried out1 each fibre would be more or less covered or varnished with greasy matter1 resisting the absorption and fixing of mordant and dye4 ,as scouring agents1 ammonia1 carbonate of ammonia1 carbonate of soda completely free from caustic1 and potash or soda soaps1 especially palm-oil soaps1 which need not be made with bleached palm oil1 but which must be quite free from free alkali1 may be used4 ,in making these palm-oil soaps it is better to err on the side of a little excess of free oil or fat1 but if more than #a per cent4 of free fat be present1 lathering qualities are then interfered with4 ,oleic acid soaps are excellent1 but are rather expensive for wool2 they are generally used for silks4 ,either as a skin soap or a soap for scouring wools1 ,i should prefer one containing about #a_/b per cent4 of free fatty matter1 of course perfectly equally distributed1 and not due to irregular saponification4 ,on the average the soap solution for scouring wool may contain about #f-a_/b oz4 of soap to the gallon of water4 ,in order to increase the cleansing powers of the soap solution1 some ammonia may be added to it4 ,however1 if soap is used for wool-scouring1 one thing must be borne in mind1 namely1 that the water used must not be hard1 for if insoluble lime and magnesia soaps are formed and precipitated on the fibre1 the scouring will have removed one evil1 but replaced it by another4 ,the principal scouring material used is one of the various forms of commercial carbonate of soda1 either alone or in conjunction with soap4 ,whatever be the form or name under which the carbonate of soda is sold1 it must be free from hydrate of soda1 i4e4 caustic soda1 or1 as it is also termed1 causticity4 ,by using this carbonate of soda you may dispense with soap1 and so be able1 even with a hard or calcareous water1 to do your wool-scouring without anything like the ill effects that follow the use of soap and calcareous water4 ,the carbonate of soda solutions ought not to exceed the specific gravity of #a to #b ,twaddell 7#a-a_/b to #c oz4 avoird4 per gallon of water74 ,the safest plan is to work with as considerable a degree of dilution and as low a temperature as are consistent with fetching the dirt and grease off4 ,the scouring of loose wool1 as we may now readily discern1 divides itself into three stages3 #ast1 the stage in which those yolk or suint constituents soluble in water1 are removed by steeping and washing in water4 ,this operation is generally carried out by the wool-grower himself1 for he desires to sell wool1 and not wool plus yolk or suint1 and thus he saves himself considerable cost in transport4 ,the water used in this process should not be at a higher temperature than #aac ,f41 and the apparatus ought to be provided with an agitator2 #bnd1 the cleansing or scouring proper1 with a weak alkaline solution2 #crd1 the rinsing or final washing in water4 ,thus far we have proceeded along the same lines as the woollen manufacturer1 but now we must deviate from that course1 for he requires softness and delicacy for special purposes1 for spinning and weaving1 etc42 but the felt manufacturer1 and especially the manufacturer of felt for felt hats1 requires to sacrifice some of this softness and delicacy in favour of greater felting powers1 which can only be obtained by raising the scales of the fibres by means of a suitable process1 such as treatment with acids4 ,this process is one which is by no means unfavourable to the dyeing capacities of the wool2 on the whole it is decidedly favourable4 ,so far everything in the treatment of the wool has been perfectly favourable for the subsequent operations of the felt-hat dyer1 but now ,i come to a process which ,i consider ,i should be perfectly unwarranted in passing over before proceeding to the dyeing processes4 ,in fact1 were it not for this proofing process 7see ,lecture ,,vii47 the dyeing of felt hats would be as simple and easy of attainment as the ordinary dyeing of whole-wool fabrics4 ,instead of this1 however1 ,i consider the hat manufacturer1 as regards his dyeing processes as applied to the stiffer classes of felt hats1 has difficulties to contend with fully comparable with those which present themselves to the dyer of mixed cotton and woollen or ,bradford goods4 ,you have heard that the purpose of the wool-scourer is to remove the dirt1 grease1 and so-called yolk1 filling the pores and varnishing the fibres4 ,now the effect of the work of the felt or felt-hat proofer is to undo nearly all this for the sake of rendering the felt waterproof and stiff4 ,the material used1 also1 is even more impervious and resisting to the action of aqueous solutions of dyes and mordants than the raw wool would be4 ,in short1 it is impossible to mordant and to dye shellac by any process that will dye wool4 ,to give you an idea of what it is necessary to do in order to colour or dye shellac1 take the case of coloured sealing-wax1 which is mainly composed of shellac1 four parts1 and ,venice turpentine1 one part4 ,to make red sealing-wax this mixture is melted1 and three parts of vermilion1 an insoluble metallic pigment1 are stirred in4 ,if black sealing-wax is required1 lamp-black or ivory-black is stirred in4 ,the fused material is then cast in moulds1 from which the sticks are removed on cooling4 ,that is how shellac may be coloured as sealing-wax1 but it is a totally different method from that by which wool is dyed4 ,the difficulty then is this--in proofing1 your hat-forms are rendered impervious to the dye solutions of your dye-baths1 all except a thin superficial layer1 which then has to be rubbed down1 polished1 and finished4 ,thus in a short time1 since the bulk of that superficially dyed wool or fur on the top of every hat is but small1 and has been much reduced by polishing and rubbing1 you soon hear of an appearance of bareness--,i was going to say threadbareness--making itself manifest4 ,this is simply because the colour or dye only penetrates a very little way down into the substance of the felt1 until1 in fact1 it meets the proofing1 which1 being as it ought to be1 a waterproofing1 cannot be dyed4 ,it cannot be dyed either by ,english or ,german methods2 neither logwood black nor coal-tar blacks can make any really good impression on it4 ,cases have often been described to me illustrating the difficulty in preventing hats which have been dyed black with logwood1 and which are at first a handsome deep black1 becoming rather too soon of a rusty or brownish shade4 ,now my belief is that two causes may be found for this deterioration4 ,one is the unscientific method adopted in many works of using the same bath practically for about a month together without complete renewal4 ,during this time a large quantity of a muddy precipitate accumulates1 rich in hydrated oxide of iron or basic iron salts of an insoluble kind4 ,this mud amounts to no less than #be per cent4 of the weight of the copperas used4 ,from time to time carbonate of ammonia is added to the bath1 as it is said to throw up dirt4 ,the stuff or dirt1 chiefly an ochre-like mass stained black with the dye1 and rich in iron and carbonate of iron1 is skimmed off1 and fresh verdigris and copperas added with another lot of hat-forms4 ,no doubt on adding fresh copperas further precipitation of iron will take place1 and so this ochre-like precipitate will accumulate1 and will eventually come upon the hats like a kind of thin black mud4 ,now the effect of this will be that the dyestuff1 partly in the fibre as a proper dye1 and not a little on the fibre as if smudged on or painted on1 will1 on exposure to the weather1 moisture1 air1 and so on1 gradually oxidise1 the great preponderance of iron on the fibre changing to a kind of iron-rust1 corroding the fibres in the process1 and thus at once accounting for the change to the ugly brownish shade1 and to the rubbing off and rapid wearing away of the already too thin superficial coating of dyed felt fibre4 ,in the final spells of dyeing in the dye-beck already referred to1 tolerably thick with black precipitate or mud1 the application of black to the hat-forms begins1 ,i fear1 to assume at length a too close analogy to another blacking process closely associated with a pair of brushes and the time-honoured name of ,day ,martin4 ,with that logwood black fibre1 anyone could argue as to a considerable proportion of the dye rubbing1 wearing1 or washing off4 ,thus1 then1 we have the second cause of the deterioration of the black1 for the colour could not go into the fibre1 and so it was chiefly laid or plastered on4 ,you can also see that a logwood black hat dyer may well make the boast1 and with considerable appearance of truth1 that for the purposes of the ,english hat manufacturers1 logwood black dyeing is the most appropriate1 i4e4 for the dyeing of highly proofed and stiff goods1 but as to the permanent character of the black colour on those stiff hats1 there you have quite another question4 ,i firmly believe that in order to get the best results either with logwood black or aniline blacks1 it is absolutely necessary to have in possession a more scientific and manageable process of proofing4 ,such a process is that invented by ,f4,w4 ,cheetham 7see ,lecture ,,vii4 p4 #ff74 ,in the dyeing of wool and felt with coal-tar colours1 it is in many cases sufficient to add the solution of the colouring matters to the cold or tepid water of the dye-bath1 and1 after introducing the woollen material1 to raise the temperature of the bath4 ,the bath is generally heated to the boiling-point1 and kept there for some time4 ,a large number of these coal-tar colours show a tendency of going so rapidly and greedily on to the fibre that it is necessary to find means to restrain them4 ,this is done by adding a certain amount of ,glauber's salts 7sulphate of soda71 in the solution of which coal-tar colours are not so soluble as in water alone1 and so go more slowly1 deliberately1 and thus evenly upon the fibre4 ,it is usually also best to dye in a bath slightly acid with sulphuric acid1 or to add some bisulphate of soda4 ,there is another point that needs good heed taking to1 namely1 in using different coal-tar colours to produce some mixed effect1 or give some special shade1 the colours to be so mixed must possess compatibility under like circumstances4 ,for example1 if you want a violet of a very blue shade1 and you take ,methyl ,violet and dissolve it in water and then add ,aniline ,blue also in solution1 you find that precipitation of the colour takes place in flocks4 ,a colouring matter which requires1 as some do1 to be applied in an acid bath1 ought not to be applied simultaneously with one that dyes best in a neutral bath4 ,numerous descriptions of methods of using coal-tar dyestuffs in hat-dyeing are available in different volumes of the ,journal of the ,society of ,chemical ,industry1 and also tables for the detection of such dyestuffs on the fibre4 ,now ,i will mention a process for dyeing felt a deep dead black with a coal-tar black dye which alone would not give a deep pure black1 but one with a bluish-purple shade4 ,to neutralise this purple effect1 a small quantity of a yellow dyestuff and a trifle of indigotin are added4 ,a deep black is thus produced1 faster to light than logwood black it is stated1 and one that goes on the fibre with the greatest ease4 ,but ,i have referred to the use of small quantities of differently coloured dyes for the purpose of neutralising or destroying certain shades in the predominating colour4 ,now ,i am conscious that this matter is one that is wrapped in complete mystery1 and far from the true ken of many of our dyers2 but the rational treatment of such questions possesses such vast advantages1 and pre-supposes a certain knowledge of the theory of colour1 of application and advantage so equally important1 that ,i am persuaded ,i should not close this course wisely without saying a few words on that subject1 namely1 the optical properties of colours4 ,colour is merely an impression produced upon the retina1 and therefore on the brain1 by various surfaces or media when light falls upon them or passes through them4 ,remove the light1 and colour ceases to exist4 ,the colour of a substance does not depend so much on the chemical character of that substance1 but rather and more directly upon the physical condition of the surface or medium upon which the light falls or through which it passes4 ,i can illustrate this easily4 ,for example1 there is a bright-red paint known as ,crooke's heat-indicating paint4 ,if a piece of iron coated with this paint be heated to about #aej ,f41 the paint at once turns chocolate brown1 but it is the same chemical substance1 for on cooling we get the colour back again1 and this can be repeated any number of times4 ,thus we see that it is the peculiar physical structure of bodies which appear coloured that has a certain effect upon the light1 and hence it must be from the light itself that colour really emanates4 ,originally all colour proceeds from the source of light1 though it seems to come to the eye from the apparently coloured objects4 ,but without some elucidation this statement would appear as an enigma1 since it might be urged that the light of the sun as well as that of artificial light is white1 and not coloured4 ,i hope1 however1 to show you that that light is white1 because it is so much coloured1 so variously and evenly coloured1 though ,i admit the term coloured here is used in a special sense4 ,white light contains and is made up of all the differently coloured rainbow rays1 which are continually vibrating1 and whose wave-lengths and number of vibrations distinguish them from each other4 ,we will take some white light from an electric lantern and throw it on a screen4 ,in a prism of glass we have a simple instrument for unravelling those rays1 and instead of letting them all fall on the same spot and illumine it with a white light1 it causes them to fall side by side2 in fact they all fall apart1 and the prism has actually analysed that light4 ,we get now a coloured band1 similar to that of the rainbow1 and this band is called the spectrum 7see ,fig4 #af74 ,if we could now run all these coloured rays together again1 we should simply reproduce white light4 ,we can do this by catching the coloured band in another prism1 when the light now emerging will be found to be white4 ,every part of that spectrum consists of homogeneous light1 i4e4 light that cannot be further split up4 ,the way in which the white light is so unravelled by the prism is this3 ,as the light passes through the prism its different component coloured rays are variously deflected from their normal course1 so that on emerging we have each of these coloured rays travelling in its own direction1 vibrating in its own plane4 ,it is well to remember that the bending off1 or deflection1 or refraction1 is towards the thick end of the prism always1 and that those of the coloured rays in that analysed band1 the spectrum1 most bent away from the original line of direction of the white light striking the prism1 are said to be the most refrangible rays1 and consequently are situated in the most refrangible end or part of the spectrum1 namely1 that farthest from the original direction of the incident white light4 ,these most refrangible rays are the violet1 and we pass on to the least refrangible end1 the red1 through bluish-violet1 blue1 bluish-green1 green1 greenish-yellow1 yellow1 and orange4 ,if you placed a prism say in the red part of the spectrum1 and caught some of those red rays and allowed them to pass through your prism1 and then either looked at the emerging light or let it fall on a white surface1 you would find only red light would come through1 only red rays4 ,that light has been once analysed1 and it cannot be further broken up4 ,there is great diversity of shades1 but only a limited number of primary impressions4 ,of these primary impressions there are only four--red1 yellow1 green1 and blue1 together with white and black4 ,white is a collective effect1 whilst black is the antithesis of white and the very negation of colour4 ,the first four are called primary colours1 for no human eye ever detected in them two different colours1 while all of the other colours contain two or more primary colours4 ,if we mix the following tints of the spectrum1 i4e4 the following rays of coloured light1 we shall produce white light1 red and greenish-yellow1 orange and ,prussian blue1 yellow and indigo blue1 greenish-yellow and violet4 ,all those pairs of colours that unite to produce white are termed complementary colours4 ,that is1 one is complementary to the other4 ,thus if in white light you suppress any one coloured strip of rays1 which1 mingled uniformly with all the rest of the spectral rays1 produces the white light1 then that light no longer remains white1 but is tinged with some particular tint4 ,whatever colour is thus suppressed1 a particular other tint then pervades the residual light1 and tinges it4 ,that tint which thus makes its appearance is the one which1 with the colour that was suppressed1 gave white light1 and the one is complementary to the other4 ,thus white can always be compounded of two tints1 and these two tints are complementary colours4 ,but it is important to remark here that ,i am now speaking of rays of coloured light proceeding to and striking the eye2 for a question like this might be asked3 ,you say that blue and yellow are complementary colours1 and together they produce white1 but if we mix a yellow and a blue paint or dye we have as the result a green colour4 ,how is this8 ,the cases are entirely different1 as ,i shall proceed to show4 ,in speaking of the first1 the complementary colours1 we speak of pure spectral colours1 coloured rays of light2 in the latter1 of pigment or dye colours4 ,as we shall see1 in the first1 we have an addition direct of coloured lights producing white2 in the latter1 the green colour1 appearing as the result of the mixture of the blue and yellow pigments1 is obtained by the subtraction of colours2 it is due to the absorption1 by the blue and yellow pigments1 of all the spectrum1 practically1 except the green portion4 ,in the case of coloured objects1 we are then confronted with the fact that these objects appear coloured because of an absorption by the colouring matter of every part of the rays of light falling thereupon1 except that of the colour of the object1 which colour is thrown off or reflected4 ,this will appear clearer as we proceed4 ,now let me point out a further fact and indicate another step which will show you the value of such knowledge as this if properly applied4 ,i said that if we selected from the coloured light spectrum1 separated from white light by a prism1 say1 the orange portion1 and boring a hole in our screen1 if we caught that orange light in another prism1 it would emerge as orange light1 and suffer no further analysis4 ,it cannot be resolved into red and yellow1 as some might have supposed1 it is monochromatic light1 i4e4 light purely of one colour4 ,but when a mixture of red and yellow light1 which means1 of course1 a mixture of rays of greater and less refrangibility respectively than our spectral orange1 the monochromatic orange--is allowed to strike the eye1 then we have again the impression of orange4 ,how are we to distinguish a pure and monochromatic orange colour from a colour produced by a mixture of red and yellow8 ,in short1 how are we to distinguish whether colours are homogeneous or mixed8 ,the answer is1 that this can only be done by the prism1 apart from chemical analysis or testing of the substances4 ,illustration3 ,,fig4 #af4 ,the spectroscope is a convenient prism-arrangement1 such that the analytical effect produced by that prism is looked at through a telescope1 and the light that falls on the prism is carefully preserved from other light by passing it along a tube after only admitting a small quantity through a regulated slit4 ,now all solid and liquid bodies when raised to a white heat give a continuous spectrum1 one like the prismatic band already described1 and one not interrupted by any dark lines or bands4 ,the rays emitted from the white-hot substance of the sun have to pass1 before reaching our earth1 through the sun's atmosphere1 and since the light emitted from any incandescent body is absorbed on passing through the vapour of that substance1 and since the sun is surrounded by such an atmosphere of the vapours of various metals and substances1 hence we have1 on examining the sun's spectrum1 instead of coloured bands or lines only1 many dark ones amongst them1 which are called ,fraunhofer's lines4 ,ordinary incandescent vapours from highly heated substances give discontinuous spectra1 i4e4 spectra in which the rays of coloured light are quite limited1 and they appear in the spectroscope only as lines of the breadth of the slit4 ,these are called line-spectra1 and every chemical element possesses in the incandescent gaseous state its own characteristic lines of certain colour and certain refrangibility1 by means of which that element can be recognised4 ,to observe this you place a ,bunsen burner opposite the slit of the spectroscope1 and introduce into its colourless flame on the end of a platinum wire a little of a volatile salt of the metal or element to be examined4 ,the flame of the lamp itself is often coloured with a distinctiveness that is sufficient for a judgment to be made with the aid of the naked eye alone1 as to the metal or element present4 ,thus soda and its salts give a yellow flame1 which is absolutely yellow or monochromatic1 and if you look through your prism or spectroscope at it1 you do not see a coloured rainbow band or spectrum1 as with daylight or gaslight1 but only one yellow double line1 just where the yellow would have been if the whole spectrum had been represented4 ,i think it is now plain that for the sake of observations and exact discrimination1 it is necessary to map out our spectrum1 and accordingly1 in one of the tubes1 the third1 the spectroscope is provided with a graduated scale1 so adjusted that when we look at the spectrum we also see the graduations of the scale1 and so our spectrum is mapped2 the lines marked out and named with the large and small letters of the alphabet1 are certain of the prominent ,fraunhofer's lines 7see ,a1 ,b1 ,c1 a1 d1 etc41 ,fig4 #af74 ,we speak1 for example1 of the soda yellow-line as coinciding with ,d of the spectrum4 ,these1 then1 are spectra produced by luminous bodies4 ,the colouring matters and dyes1 their solutions1 and the substances dyed with them1 are not1 of course1 luminous1 but they do convert white light which strikes upon or traverses them into coloured light1 and that is why they1 in fact1 appear either as coloured substances or solutions4 ,the explanation of the coloured appearance is that the coloured substances or solutions have the power to absorb from the white light that strikes or traverses them1 all the rays of the spectrum but those which are of the colour of the substance or solution in question1 these latter being thrown off or reflected1 and so striking the eye of the observer4 ,take a solution of ,magenta1 for example1 and place a light behind it4 ,all the rays of that white light are absorbed except the red ones1 which pass through and are seen4 ,thus the liquid appears red4 ,if a dyed piece be taken1 the light strikes it1 and if a pure red1 from that light all the rays but red are absorbed1 and so red light alone is reflected from its surface4 ,but this is not all with a dyed fabric1 for here the light is not simply reflected light2 part of it has traversed the upper layers of that coloured body1 and is then reflected from the interior1 losing a portion of its coloured rays by absorption4 ,this reflected coloured light is always mixed with a certain amount of white light reflected from the actual surface of the body before penetrating its uppermost layer4 ,thus1 if dyed fabrics are examined by the spectroscope1 the same appearances are generally observed as with the solution of the corresponding colouring matters4 ,an absorption spectrum is in each case obtained1 but the one from the solution is the purer1 for it does not contain the mixed white light reflected from the surfaces of coloured objects4 ,let us now take an example4 ,we will take a cylinder glass full of picric acid in water1 and of a yellow colour4 ,now when ,i pass white light through that solution and examine the emerging light1 which looks1 to my naked eye1 yellow1 ,i find by the spectroscope that what has taken place is this3 the blue part of the spectrum is totally extinguished as far as ,g and #b_/c of ,f4 ,that is all4 ,then why1 say you1 does that liquid look yellow if all the rest of those rays pass through and enter the eye1 namely1 the blue-green with a trifle of blue1 the green1 yellow1 orange1 and red8 ,the reason is this3 we have already seen that the colours complementary to1 and so producing white light with red1 are green and greenish-blue or bluish-green4 ,hence these cancel1 so to say1 and we only see yellow4 ,we do not see a pure yellow1 then1 in picric acid1 but yellow with a considerable amount of white4 ,here is a piece of scarlet paper4 ,why does it appear scarlet8 ,because from the white light falling upon it1 it practically absorbs all the rays of the spectrum except the red and orange ones1 and these it reflects4 ,if this be so1 then1 and we take our spectrum band of perfectly pure colours and pass our strip of scarlet paper along that variously coloured band of light1 we shall be able to test the truth of several statements ,i have made as to the nature of colour4 ,i have said colour is only an impression1 and not a reality2 and that it does not exist apart from light4 ,now1 ,i can show you more1 namely1 that the colour of the so-called coloured object is entirely dependent on the existence in the light of the special coloured rays which it radiates1 and that this scarlet paper depends on the red light of the spectrum for the existence of its redness4 ,on passing the piece of scarlet paper along the coloured band of light1 it appears red only when in the red portion of the spectrum1 whilst in the other portions1 though it is illumined1 yet it has no colour1 in fact it looks black4 ,hence what ,i have said is true1 and1 moreover1 that red paper looks red because1 as you see1 it absorbs and extinguishes all the rays of the spectrum but the red ones1 and these it radiates4 ,a bright green strip of paper placed in the red has no colour1 and looks black1 but transferred to the pure green portion it radiates that at once1 does not absorb it as it did the red1 and so the green shines out finely4 ,i have told you that sodium salts give to a colourless flame a fine monochromatic or pure yellow colour4 ,now1 if this be so1 and if all the light available in this world were of such a character1 then such a colour as blue would be unknown4 ,we will now ask ourselves another question1 ,we have a new blue colouring matter1 and we desire to know if we may expect it to be one of the greatest possible brilliancy1 what spectroscopic conditions ought it to fulfil8 ,on examining a solution of it1 or rather the light passing through a solution of it1 with the spectroscope1 we ought to find that all the rays of the spectrum lying between and nearly to ,h and b 7,fig4 #af71 i4e4 all the bluish-violet1 blue1 and blue-green rays pass through it unchanged1 unabsorbed1 whilst all the rest should be completely absorbed4 ,in like manner a pure yellow colour would allow all the rays lying between orange-red and greenish-yellow 7,fig4 #af7 to pass through unchanged1 but would absorb all the other colours of the spectrum4 ,now we come to the1 for you1 most-important subject of mixtures of colours and their effects4 ,let us take the popular case of blue and yellow producing green4 ,we have seen that the subjective effect of the mixture of blue and yellow light on the eye is for the latter to lose sense of colour1 since colour disappears1 and we get what we term white light2 in strict analogy to this the objective effect of a pure yellow pigment and a blue is also to destroy colour1 and so no colour comes from the object to the eye2 that object appears black4 ,now the pure blue colouring matter would not yield a green with the pure yellow colouring matter1 for if you plot off the two absorption spectra as previously described1 on to the spectrum 7,fig4 #af71 you will find that all the rays would be absorbed by the mixture1 and the result would be a black4 ,but1 now1 suppose a little less pure yellow were taken1 one containing a little greenish-yellow and a trifle of green1 and also a little orange-red on the other side to red1 then whereas to the eye that yellow might be as good as the first2 now1 when mixed with a blue1 we get a very respectable green4 ,but1 and this is very important1 although of the most brilliant dyes and colours there are probably no two of these that would so unite to block out all the rays and produce black1 yet this result can easily and practically be arrived at by using three colouring matters1 which must be as different as possible from one another4 ,thus a combination of a red1 a yellow1 and a blue colouring matter1 when concentrated enough1 will not let any light pass through it1 and can thus be used for the production of blacks1 and this property is made use of in dyeing4 ,and now we see why a little yellow dye is added to our coal-tar black4 ,a purplish shade would else be produced2 the yellow used is a colour complementary to that purple1 and it absorbs just those blue and purple rays of the spectrum necessary to illuminate by radiation that purple1 and vice vers2 both yellow and purple therefore disappear4 ,in like manner1 had the black been of a greenish shade1 ,i should have added ,croceine ,orange1 which on the fabric would absorb just those green and bluish rays of light necessary to radiate from and illumine that greenish part1 and the greenish part would do the like by the orange rays2 the effects would be neutralised1 and all would fall together into black4 ,,the ,,end4 ,,index ,acetone1 #fd ,acid1 boric4 ,see ,boric acid4 carbolic4 ,see ,phenol4 colours1 mordanting1 #gd hydrochloric4 ,see ,hydrochloric acid4 nitric4 ,see ,nitric acid4 sulphuric4 ,see ,sulphuric acid4 ,acids1 distinguishing1 from alkalis1 #bc1 #di neutralisation of1 #ej properties of1 #di specific gravities of1 #di ,affinity1 chemical1 #ga ,alizarin1 #ge1 #gf1 #hj1 #hc1 #ia1 #ii blue1 #ij paste1 #ia pure1 #ia purple1 #gg red1 #gg ,alkali1 manufacture of1 by ammonia-soda process1 #ee manufacture of1 by electrolytic process1 #ef manufacture of1 by ,leblanc process1 #ec ,alkalis1 distinguishing1 from acids1 #bc1 #di neutralisation of1 #ej properties of1 #di specific gravities of1 #di ,alum1 cake1 #gc ,aluminium sulphate1 #gc ,ammonia1 #bc1 #ie ,ammonia-soda process1 #ee ,aniline1 #ia black1 #ha constitution of1 #if preparation of1 #if reaction of #ig violet #gg1 #ha ,animal fibres4 ,see ,fibres4 ,annatto1 #hc1 #he1 #hg ,anthracene1 #ij ,archil4 ,see ,orchil4 ,aurin1 #ia1 #ih ,azo dyestuffs1 #ih ,barwood1 #ii ,basic colours or dyestuffs1 mordanting1 #gf ,bast fibres4 ,see ,fibres4 ,bastose1 #d ,bastose1 distinction between1 and cellulose1 #d ,beaum hydrometer degrees1 #ca ,benzene1 #ij1 #if ,bixin1 #hh ,black-ash process1 #ed ,blue colour1 absorption spectrum of pure1 #aad ,boilers1 incrustations in1 #db ,boiling-point1 effect of pressure on1 #cb of water1 effect of dissolved salts on1 #cf of water1 effect of increase of pressure on1 #ce ,borax1 #ei tests of purity of1 #ei ,boric acid1 #eg ,boronitrocalcite1 #ei ,brasilin1 #ii ,brazil wood1 #ii ,camwood1 #ii ,carbolic acid4 ,see ,phenol4 ,carminic acid1 #gf ,carr ice-making machine1 #cb ,carrotting4 ,see ,scretage4 ,carthamic acid1 #hg ,carthamin1 #hg ,cellulose1 action of cupric-ammonium solutions on1 #e composition of1 #c distinction between1 and bastose1 #d properties of pure1 #e ,cholesterol1 #ajj ,chrome mordanting1 #gh ,chrome orange1 #hd yellow1 #hd ,chroming1 over-1 #gh ,clark's soap test1 #dc ,coal-tar1 #ij yield of valuable products from1 #ij ,cochineal1 #ge1 #gf1 #hb1 #hc1 #ii ,coerulein1 #ij ,colour1 absorption spectrum of pure blue1 #aad absorption spectrum of pure yellow1 #aad acids1 #gg bases1 #gg nature of1 #ajg ,coloured substances1 spectra of1 #aab ,colours1 acid1 mordanting of1 #gd basic1 #ge classification of1 #gi complementary1 #aji mixed1 spectra of1 #aae pigment1 #aaj primary1 #aaj spectral1 #aaj ,conditioning establishments1 #ba ,congo red1 #ga ,copper salts1 dissolving1 in iron pans1 #ci wet method of extracting1 #ch ,corrosion caused by fatty acids1 #ce ,cotton and woollen goods1 separation of mixed1 #e ,cotton fibre1 action of basic zinc chloride on1 #e composition of1 #c dimensions of1 #b stomata in cuticle of1 #b structure of1 #a ,cotton-silk fibre1 #c composition of1 #c ,crookes' heat-indicating paint1 #ajg ,cudbear1 #hf ,cupric ammonium solution1 action of1 on cellulose1 #e ,curcumin1 #hg ,dextrin1 #d ,dyeing felt hats deep black1 #ajf effect of stiffening and proofing process in1 #fe1 #ajc of wool and felt with coal-tar colours1 #aje of wool and fur1 #ajj power of coal-tar dyestuffs1 #ic with mixed coal-tar colours1 #ajf ,dyestuffs1 adjectiv1 #hc1 #ii azo1 #ih classification of1 #gi coal-tar1 #ij dyeing power of1 #ic yield of1 #ia mineral1 #hc monogenetic1 #ha pigment1 #hc polygenetic1 #hb substantive1 #hc artificial1 #hi natural1 #he ,equivalence1 law of1 #di ,fats1 decomposition of1 by superheated steam1 #ce ,felt1 dyeing1 deep black1 #ajf with coal-tar colours1 #aje ,felting1 dilute acid for promoting1 #bb effect of water in1 #ba fur1 #ae interlocking of scales in1 #ac preparation of fur for1 #ah unsuitability of dead wool for1 #ah ,fibre1 cotton4 ,see ,cotton4 cotton-silk4 ,see ,cotton-silk4 flax4 ,see ,flax4 jute4 ,see ,jute4 silk4 ,see ,silk4 wool4 ,see ,wool4 ,fibres1 action of acids on textile1 #e alkaline solution of copper and glycerin on textile1 #bh alkalis on textile1 #e caustic soda on textile 1 #bh copper-oxide-ammonia on textile1 #bh nitric acid on textile1 #bh steam on textile1 #e sulphuric acid on textile1 #bg ,fibres1 animal1 #f bast1 #c vegetable1 #a and animal1 determining1 in mixture1 #bg and animal1 distinguishing1 #d1 #e and animal1 distinguishing and separating1 #bd ,fibron1 #g ,flax fibre1 action of basic zinc chloride on1 #e composition of1 #c structure of1 #b ,fraunhofer's lines1 #aaa1 #aab ,fur1 #h action of acids on1 #bc of alkalis on1 #bd on1 in scretage process1 #ag chrome mordanting of1 #gg composition of1 #bb felting1 #ae finish and strength of felted1 effect of boiling water on1 #bb hygroscopicity of1 #bj preparation of1 for felting1 #ah scretage or carrotting of1 #ag stiffening and proofing of felted1 #ff sulphur in1 reagents for detection of1 #bf ,fustic1 #ii ,gallein1 #hb1 #hc ,gallnuts1 #ii ,garancine1 #ii ,guy-,lussac tower1 #eb ,glover tower1 #eb ,glucose1 #d ,greening of black hats1 #fe ,hmatein1 #gf1 #gh #hc1 #ii ,hair1 #h cells from1 #aa distinction between1 and wool1 #ab1 #ad dyeing1 #bf growth of1 #h scales from1 #aa of1 action of reagents on1 #ab scaly structure of1 #aa structure of1 #h1 #i sulphur in1 reagents for detection of1 #bf ,hargreaves ,robinson's process1 #ec ,hats dyed logwood black1 deterioration of1 #ajd greening of black1 #fe stiffening and proofing of1 #fc1 #fd stiffening and proofing of1 by ,cheetham's process1 #ff stiffening and proofing of1 by ,continental process1 #ff stiffening and proofing process1 effect of1 in dyeing1 #fe1 #ajc ,heat1 latent1 #cb1 #cc of steam1 #cd of water1 #cd ,heddebault's process of separating mixed cotton and woollen goods1 #e ,hydrochloric acid1 manufacture of1 by ,hargreaves ,robinson's process1 #ec manufacture of1 by salt-cake process1 #ec ,ice1 heat of liquefaction of1 #cd ,ice-making machine1 ,carr1 #cb ,indican1 #he ,indicators1 #ej1 #gj ,indigo1 #he artificial1 #hf blue1 #he recovery of1 from indigo-dyed woollen goods1 #bd vat1 #hf white1 #he ,insoluble compounds1 precipitation of1 from solutions1 #ch ,iron liquor4 ,see ,mordant1 iron4 ,jute fibre1 #c composition of1 #d ,lac1 button1 #fc dye1 #fb1 #ii seed1 #fb stick1 #fb ,see also ,shellac4 ,lakes1 colour1 #ge ,latent heat4 ,see ,heat4 ,leblanc process1 #ec ,light1 analysis of white1 #ajg composition of white1 #ajg homogeneous or monochromatic1 #ajh1 #aaj rays1 refraction of1 #ajh ,linen fibre4 ,see ,flax4 ,litmus1 #gj1 #hf ,logwood1 #ge1 #gf1 #gh1 #hc1 #ii ,logwood black1 #gh1 #ha1 #ajd deterioration of hats dyed with1 #ajd ,madder1 #hj1 #hc1 #ii ,magenta1 #gf1 #hj1 #hc1 #ia1 #ig ,marsh gas1 #ie ,mercuric nitrate1 use of1 for the scretage of fur1 #ag ,merino wool1 #ae ,methane4 ,see ,marsh gas4 ,methyl alcohol4 ,see ,wood spirit4 green1 #ig violet1 #ig ,mirbane1 essence of1 #if ,molisch's test1 #d ,mordant1 alumina1 #fd1 #ge antimony1 #gf iron1 #fd1 #gf tannin1 #gf tin1 #gf ,mordanting acid 7phenolic7 colours1 #gd basic colours1 #gf chrome1 #gg woollen fabrics1 #ge ,mordants1 #fi fatty acid1 #gg ,naphthalene1 #ij1 #ih ,naphthol yellow1 #ia ,naphthols1 #ia1 #ih ,naphthylamine1 #ia ,nitric acid1 #ie manufacture of1 #eb ,nitrobenzene1 #if ,nitroprusside of soda1 #bf ,oils1 decomposition of1 by superheated steam1 #ce ,orcin1 #hf ,orchil1 #he1 #hf ,orcin1 #hf ,orellin1 #hh ,over-chroming1 ,see ,chroming4 ,paint1 ,crookes' heat-indicating1 #ajg ,persian berries1 #ge1 #ii ,phenol1 #ij constitution of1 #ih ,phenolic colours4 ,see ,acid colours4 ,phenolphthalein1 #gj ,picric acid1 #ha1 #ia absorption spectrum of1 #aac constitution of1 #ih ,plumbate of soda1 #bf ,potassium1 decomposition of water by1 #be1 #cj ,proofing mixture1 #fc process1 #fd ,cheetham's1 #ff ,continental1 #ff effect of1 in dyeing1 #fe1 #ajc ,purpurin1 #ii ,quercitron1 #ii ,red liquor4 ,see ,mordant1 alumina4 ,refraction of light rays1 #ajh ,safflower1 #he1 #hg ,salt-cake process1 #ec ,salts1 #di acid1 #gj1 #ga basic1 #ga neutral or normal1 #ga stable1 #gb unstable1 #gb ,santalin1 #ii ,santalwood1 #ii ,sealing-wax1 coloured1 #ajc ,scretage of fur1 #ag process1 injury to fur in1 #ag ,sericin1 #g ,shellac1 #fb colouring of1 #ajc rosin in1 detection of1 #fc solvents for1 #fc ,see also ,lac4 ,silk fibre1 action of acids on1 #g of alkaline solution of1 copper and glycerin on1 #g of alkalis on1 #g of basic zinc chloride on1 #g bleaching of1 #g composition of1 #g structure of1 #f ungumming of1 #g glue1 #g gum1 #g ,soap1 #fj alkali in1 detection of1 #fa oleic acid1 #aja palm oil1 #aja water in1 determination of1 #fj ,soda4 ,see ,alkali4 ,solution1 #cf precipitation of insoluble compounds from1 #ch ,specific gravity1 #cj ,spectra of coloured substances #aab ,spectroscope1 #aaa ,spectrum1 #ajh absorption1 #aac continuous1 #aaa discontinuous or line1 #aaa ,spirits of salt4 ,see ,hydrochloric acid4 ,starch1 #d ,steam1 #ca latent heat of1 #cd ,stiffening mixture1 #fc process1 #fd ,cheetham's1 #ff ,continental1 #ff effect of1 in dyeing #fe1 #ajc ,suint4 ,see ,wool grease4 ,sulphur in wool1 fur1 and hair1 reagents for detection of1 #bf ,sulphuric acid1 manufacture of1 #ej by contact process1 #eb by lead chamber process1 #ea ,sumach1 #ii ,tannins1 #ii ,tincal1 #ei ,tiza1 #ei ,toluene1 #ij ,toluidine1 #ia ,turmeric1 #hj1 #hc1 #he1 #hg ,twaddell hydrometer degrees1 #ca ,ultramarine blue1 #ha ,ultramarine green1 #ha rose-coloured1 #ha ,valency1 #ga ,vegetable fibres4 ,see ,fibres4 ,veneering process1 #ff ,vermilline scarlet1 #ia ,vitriol4 ,see ,sulphuric acid4 ,water1 #bi boiling of #ca boiling-point of1 effect of dissolved salts on #cf boiling-point of1 effect of increase of pressure on1 #ce chlorides in1 detection of1 #dg composition of1 #bi contamination of1 by factories1 #de copper in1 detection of1 #df decomposition of1 by potassium1 #be1 #cj filtration of1 #dg hard1 #da1 #db ,clark's soap test for1 #dc softening of1 #da waste of soap by1 #dc hardness1 temporary and permanent1 of1 #db impurities in1 #db effect of1 in dyeing1 #db ferruginous1 #dd iron in1 detection of1 #df latent heat of1 #cd lead in1 detection of1 #dg lime in1 detection of1 #df magnesium in1 detection of1 #df purification of1 #de purity of1 tests for1 #df soft1 #dj effect of carbonic acid in hardening1 #dj sulphates in1 detection of1 #bd ,wood acid1 #fd destructive distillation of1 #fd spirit1 #fd ,wool1 chrome mordanting of1 #gg dead3 why it will not felt1 #ah dyeing1 with coal-tar colours1 #aje felted1 effect of boiling water on finish and strength of1 #bb felted1 effect of stiffening process on finish of1 #ff1 #ajc felting of1 interlocking of scales in1 #ac fibre1 #h action of acids on1 #bc of alkalis on1 #bd composition of1 #bb curly structure of1 #ae distinction between1 and hair1 #ab1 #ad growth of1 #h hygroscopicity of1 #bj structure of1 from diseased sheep1 #ai sulphur in1 reagents for detection of1 #bf grease1 #ajj kempy1 #ai merino1 #ae mordanting1 #ge scouring1 #aja stripping of1 #bc ,woollen goods1 indigo-dyed1 recovery of indigo from1 #bd mixed cotton and1 separation of1 #e ,xylenes1 #ij ,yellow colour1 absorption spectrum of pure1 #aad ,yolk4 ,see ,wool grease4 ,abridged ,catalogue ,,of ,special ,technical ,books4 ,,index ,,to ,,subjects4 ,,page ,agricultural ,chemistry1 #i ,air1 ,industrial ,use of1 #aj ,alum and its ,sulphates1 #h ,ammonia1 #h ,aniline ,colours1 #c ,animal ,fats1 #f ,anti-corrosive ,paints1 #d ,architecture1 ,terms in1 #bb ,architectural ,pottery1 #ab ,artificial ,perfumes1 #g ,balsams1 #i ,bleaching1 #ag ,bleaching ,agents1 #ag ,bone ,products1 #h ,bookbinding1 #bc ,brick-making1 #aa1 #ab ,burnishing ,brass1 #bj ,carpet ,yarn ,printing1 #af ,casein1 #d ,celluloid1 #bc ,cement1 #bb ,ceramic ,books1 #aa ,charcoal1 #h ,chemical ,essays1 #h ,chemical ,works1 #h ,chemistry of ,pottery1 #ab ,clay ,analysis1 #ab ,coal dust ,firing1 #ai ,colour ,matching1 #af ,colliery ,recovery ,work1 #ah ,colour-mixing for ,dyers1 #af ,colour ,theory1 #af ,combing ,machines1 #ah ,compounding ,oils1 #f ,condensing ,apparatus1 #ai ,cosmetics1 #g ,cotton ,dyeing1 #ag ,cotton ,spinning1 #ag1 #ah ,cotton ,waste1 #ah ,damask ,weaving1 #ae ,dampness in ,buildings1 #bb ,decorators' ,books1 #d ,decorative ,textiles1 #ae ,dental ,metallurgy1 #ai ,drugs1 #bb ,drying ,oils1 #e ,drying with ,air1 #aj ,dyeing ,marble1 #bc ,dyeing ,woollen ,fabrics1 #ag ,dyers' ,materials1 #af ,dye-stuffs1 #ag ,edible ,fats and ,oils1 #g ,electric ,wiring1 #bj1 #ba ,electricity in ,collieries1 #ai ,emery1 #bd ,enamelling ,metal1 #ac1 #ba ,enamels1 #ac ,engineering ,handbooks1 #bj ,engraving1 #bc ,essential ,oils1 #g ,evaporating ,apparatus1 #i ,external ,plumbing1 #bj ,fats1 #f ,faults in ,woollen ,goods1 #ae ,flax ,spinning1 #ah ,food and ,drugs1 #bb ,fruit ,preserving1 #bb ,gas ,firing1 #ai ,glass-making ,recipes1 #ac ,glass ,painting1 #ac ,glue-making and ,testing1 #h ,greases1 #f ,gutta ,percha1 #aa ,hat ,manufacturing1 #ae ,hemp ,spinning1 #ah ,history of ,staffs ,potteries #ab ,hops1 #ba ,hot-water ,supply1 #ba ,india-rubber1 #aa ,industrial ,alcohol1 #i ,inks1 #c1 #d1 #e1 #i ,iron-corrosion1 #d ,iron1 ,science of1 #ai ,japanning1 #ba ,jute ,spinning1 #ah ,lace-,making1 #ae ,lacquering1 #bj ,lake ,pigments1 #c ,lead and its ,compound1 #aj ,leather-working ,mater'ls1 #f1 #aa ,libraries1 #bd ,linoleum1 #e ,lithography1 #bc ,lubricants1 #f ,manures1 #h1 #i ,meat ,preserving1 #bb ,mineral ,pigments1 #c ,mineral ,waxes1 #f ,mine ,ventilation1 #ah ,mine ,haulage1 #ah ,mining1 ,electricity1 #ai ,needlework1 #ae ,oil and ,colour ,recipes1 #c ,oil ,boiling1 #e ,oil ,merchants' ,manual1 #f ,oils1 #f ,ozone1 ,industrial ,use of1 #aj ,paint ,manufacture1 #c ,paint ,materials1 #c ,paint-material ,testing1 #d ,paint ,mixing1 #c ,paper-,mill ,chemistry1 #ac ,paper-pulp ,dyeing1 #ac ,petroleum1 #f ,pigments1 ,chemistry of1 #c ,plumbers' ,work1 #bj ,pottery ,clays1 #ab ,pottery ,decorating1 #aa ,pottery ,manufacture1 #aa ,pottery ,marks1 #ab ,power-loom ,weaving1 #ad ,preserved ,foods1 #bb ,printers' ,ready ,reckoner #bc ,printing ,inks1 #c1 #d1 #e ,recipes1 #c ,resins1 #i ,ring ,spinning ,frame1 #ah ,risks of ,occupations1 #aj ,riveting ,china1 etc41 #ab ,sanitary ,plumbing1 #bj ,scheele's ,essays1 #h ,sealing ,waxes1 #i ,shale ,tar ,distillation1 #h ,shoe ,polishes1 #f ,silk ,dyeing1 #ag ,silk ,throwing1 #ag ,smoke ,prevention1 #ai ,soaps1 #g ,spinning1 #ae1 #ag1 #ah ,spirit ,varnishes1 #e ,staining ,marble1 and ,bone1 #bc ,steam ,drying1 #aj ,steel ,hardening1 #ai ,sugar ,refining1 #bc ,sweetmeats1 #bb ,technical ,schools1 ,list1 #bd ,terra-cotta1 #aa ,testing ,paint ,materials1 #d ,testing ,yarns1 #ae ,textile ,fabrics1 #ad1 #ae ,textile ,fibres1 #ad ,textile ,materials1 #ad ,timber1 #ba ,varnishes1 #e ,vegetable ,fats1 #g ,vegetable ,preserving1 #bb ,warp ,sizing1 #af ,waste ,utilisation1 #i ,water1 ,industrial ,use1 #aj ,water-proofing ,fabrics1 #af ,waxes1 #f ,weaving ,calculations1 #ae ,white ,lead and ,zinc1 #e ,wood ,distillation1 #ba ,wood ,extracts1 #ba ,wood ,waste ,utilisation1 #bb ,wood-,dyeing1 #bc ,wool-,dyeing1 #ag ,woollen ,goods1 #ae1 #af1 #ag ,writing ,inks1 #i ,x-,ray ,work1 #aa ,yarn ,sizing1 #af ,yarn ,testing1 #ae ,zinc ,white ,paints1 #e ,,published ,,by ,,scott1 ,,greenwood ,,son #h ,,broadway1 ,,ludgate1 ,,london1 ,e4,c4 ,,full ,,particulars ,,of ,,contents ,of the ,books mentioned in this ,,abridged ,,catalogue will be found in the following ,catalogues of ,,current ,,technical ,,books4 ,,list ,i4 ,artists' ,colours--,bone ,products--,butter and ,margarine ,manufacture--,casein--,cements--,chemic al ,works 7,designing and ,erection7--,chemistry 7,agricultural1 ,industrial1 ,practical and ,theoretical7--,colour ,mixing--,colour ,manufacture--,compounding ,oils--,decorating--,driers--,drying ,oils--,drysaltery--,emery--,essential ,oils--,fats 7,animal1 ,vegetable1 ,edible7--,gelatines--,glues--,greases-- ,gums--,inks--,lead--,leather--,lubrican ts--,oils--,oil ,crushing--,paints--,paint ,manufacturing--,paint ,material ,testing--,perfumes--,petroleum--,pharma cy-- ,recipes 7,paint1 ,oil and ,colour7--,resins--,sealing ,waxes--,shoe ,polishes--,soap ,manufacture--,solvents--,spirit ,varnishes--,varnishes--,white ,lead--,workshop ,wrinkles4 ,,list ,,ii4 ,bleaching--,bookbinding--,carpet ,yarn ,printing--,colour 7,matching1 ,mixing1 ,theory7--,cotton ,combing ,machines--,dyeing 7,cotton1 ,woollen and ,silk ,goods7--,dyers' ,materials--,dye-stuffs--,engraving--,fl ax1 ,hemp and ,jute ,spinning and ,twisting--,gutta-,percha--,hat ,manufacturing--,india-rubber--,inks--,l ace-making--,lithography--,needlework--, paper ,making--,paper-,mill ,chemist--,paper-pulp ,dyeing--,point ,lace--,power-loom ,weaving--,printing ,inks--,silk ,throwing--,smoke ,prevention--,soaps--,spinning--,textile 7,spinning1 ,designing1 ,dyeing1 ,weaving1 ,finishing7--,textile ,materials--,textile ,fabrics--,textile ,fibres--,textile ,oils--,textile ,soaps--,timber--,water 7,industrial ,uses7--,water-proofing--,weaving--,writ ing ,inks--,yarns 7,testing1 ,sizing74 ,,list ,,iii4 ,architectural ,terms--,brassware 7,bronzing1 ,burnishing1 ,dipping1 ,lacquering7--,brickmaking--,building--, cement ,work--,ceramic ,industries--,china--,coal-dust ,firing--,colliery ,books--,concrete--,condensing ,apparatus--,dental ,metallurgy--,drainage--,drugs--,dyeing- -,earthenware--,electrical ,books--,enamelling--,enamels--,engineer ing ,handbooks--,evaporating ,apparatus--,flint ,glass-making--,foods--,food ,preserving--,fruit ,preserving--,gas ,engines--,gas ,firing--,gearing--,glassware 7,painting1 ,riveting7--,hops--,iron 7,construction1 ,science7--,japanning--,lead--,meat ,preserving--,mines 7,haulage1 ,electrical ,equipment1 ,ventilation1 ,recovery ,work from7--,plants 7,diseases1 ,fungicides1 ,insecticides7--,plumbing ,books--,pottery 7,architectural1 ,clays1 ,decorating1 ,manufacture1 ,marks on7--,reinforced ,concrete--,riveting 7,china1 ,earthenware1 ,glassware7--,steam ,turbines--,sanitary ,engineering--,steel 7,hardening1 ,tempering7--,sugar--,sweetmeats--,tooth ed ,gearing--,vegetable ,preserving--,wood ,dyeing--,x-,ray ,work4 ,,copies ,,of ,,any ,,of ,,these ,,lists ,,will ,,be ,,sent ,,post ,,free ,,on ,,application4 7,paints1 ,colours1 ,pigments and ,printing ,inks47 ,,the ,,chemistry ,,of ,,pigments4 ,by ,,ernest ,j4 ,,parry1 ,b4,sc4 7,lond471 ,f4,i4,c41 ,f4,c4,s41 and ,j4,h4 ,,coste1 ,f4,i4,c41 ,f4,c4,s4 ,demy #hvo4 ,five ,illustrations4 #bhe pp4 ,price #ajs4 #f;d4 net4 7,post free1 #ajs4 #aj;d4 home2 #aas4 #c;d4 abroad47 ,,the ,,manufacture ,,of ,,paint4 ,a ,practical ,handbook for ,paint ,manufacturers1 ,merchants and ,painters4 ,by ,j4 ,,cruickshank ,,smith1 ,b4,sc4 ,demy #hvo4 #bjj pp4 ,sixty ,illustrations and ,one ,large ,diagram4 ,price #gs4 #f;d4 net4 7,post free1 #gs4 #aj;d4 home2 #hs4 abroad47 ,,dictionary ,,of ,,chemicals ,,and ,,raw ,,products ,,used ,,in ,,the ,,manufacture ,,of ,,paints1 ,,colours1 ,,varnishes ,,and ,,allied ,,preparations4 ,by ,,george ,h4 ,,hurst1 ,f4,c4,s4 ,demy #hvo4 #chj pp4 ,price #gs4 #f;d4 net4 7,post free1 #hs4 home2 #hs4 #f;d4 abroad47 ,,the ,,manufacture ,,of ,,lake ,,pigments ,,from ,,artificial ,,colours4 ,by ,,francis ,h4 ,,jennison1 ,f4,i4,c41 ,f4,c4,s4 ,sixteen ,coloured ,plates1 showing ,specimens of ,eighty-nine ,colours1 specially prepared from the ,recipes given in the ,book4 #acf pp4 ,demy #hvo4 ,price #gs4 #f;d4 net4 7,post free1 #gs4 #aj;d4 home2 #hs4 abroad47 ,,the ,,manufacture ,,of ,,mineral ,,and ,,lake ,,pigments4 ,containing ,directions for the ,manufacture of all ,artificial1 ,artists and ,painters' ,colours1 ,enamel1 ,soot and ,metallic ,pigments4 ,a text-book for ,manufacturers1 ,merchants1 ,artists and ,painters1 ,by ,dr4 ,,josef ,,bersch4 ,translated by ,a4,c4 ,,wright1 ,m4,a4 7,oxon471 ,b4,sc4 7,lond474 ,forty-three ,illustrations4 #dgf pp4 ,demy #hvo4 ,price #abs4 #f;d4 net4 7,post free1 #acs4 home2 #acs4 #f;d4 abroad47 ,,recipes ,,for ,,the ,,colour1 ,,paint1 ,,varnish1 ,,oil1 ,,soap ,,and ,,drysaltery ,,trades4 ,compiled by ,,an ,,analytical ,,chemist4 #cej pp4 ,second ,revised ,edition4 ,demy #hvo4 ,price #ajs4 #f;d4 net4 7,post free1 #aas4 home2 #aas4 #c;d4 abroad47 ,,oil ,,colours ,,and ,,printers' ,,inks4 ,by ,,louis ,,edgar ,,and,s4 ,translated from the ,german4 #bae pp4 ,crown #hvo4 #ef ,illustrations4 ,price #es4 net4 7,post free1 #es4 #d;d4 home2 #es4 #f;d4 abroad47 ,,modern ,,printing ,,inks4 ,a ,practical ,handbook for ,printing ,ink ,manufacturers and ,printers4 ,by ,,alfred ,,seymour4 ,demy #hvo4 ,six ,illustrations4 #ij pages4 ,price #es4 net4 7,post free1 #es4 #d;d4 home2 #es4 #f;d4 abroad47 ,,three ,,hundred ,,shades ,,and ,,how ,,to ,,mix ,,them4 ,for ,architects1 ,painters and ,decorators4 ,by ,a4 ,,desaint1 ,artistic ,interior ,decorator of ,paris4 ,the book contains #ajj folio ,plates1 measuring #ab in4 by #g in41 each ,plate containing specimens of three artistic shades4 ,these shades are all numbered1 and their composition and particulars for mixing are fully given at the beginning of the book4 ,each ,plate is interleaved with grease-proof paper1 and the volume is very artistically bound in art and linen with the ,shield of the ,painters' ,guild impressed on the cover in gold and silver4 ,price #bas4 net4 7,post free1 #bas4 #f;d4 home2 #bbs4 #f;d4 abroad47 ,,house ,,decorating ,,and ,,painting4 ,by ,w4 ,,norman ,,brown4 ,eighty-eight ,illustrations4 #aej pp4 ,crown #hvo4 ,price #cs4 #f;d4 net4 7,post free1 #cs4 #i;d4 home and abroad47 ,a ,,history ,,of ,,decorative ,,art4 ,by ,w4 ,,norman ,,brown4 ,thirty-nine ,illustrations4 #if pp4 ,crown #hvo4 ,price #as4 net4 7,post free1 #as4 #c;d4 home and abroad47 ,,workshop ,,wrinkles4 for ,decorators1 ,painters1 ,paperhangers1 and ,others4 ,by ,w4,n4 ,,brown4 ,crown #hvo4 #abh pp4 ,second ,edition4 ,price #bs4 #f;d4 net4 7,post free1 #bs4 #i;d4 home2 #bs4 #aj;d4 abroad47 ,,casein4 ,by ,,robert ,,scherer4 ,translated from the ,german by ,,chas4 ,,salter4 ,demy #hvo4 ,illustrated4 ,second ,revised ,english ,edition4 #afj pp4 ,price #gs4 #f;d4 net4 7,post free1 #gs4 #aj;d4 home2 #hs4 abroad47 ,,simple ,,methods ,,for ,,testing ,,painters' ,,materials4 ,by ,a4,c4 ,,wright1 ,m4,a4 7,oxon4741 ,b4,sc4 7,lond474 ,crown #hvo4 #afj pp4 ,price #es4 net4 7,post free1 #es4 #c;d4 home2 #es4 #f;d4 abroad47 ,,iron-,,corrosion1 ,,anti-,,fouling ,,and ,,anti-,,corrosive ,,paints4 ,translated from the ,german of ,,louis ,,edgar ,,and,s4 ,sixty-two ,illustrations4 #bge pp4 ,demy #hvo4 ,price #ajs4 #f;d4 net4 7,post free1 #ajs4 #aj;d4 home2 #aas4 #c;d4 abroad47 ,,the ,,testing ,,and ,,valuation ,,of ,,raw ,,materials ,,used ,,in ,,paint ,,and ,,colour ,,manufacture4 ,by ,m4,w4 ,,jones1 ,f4,c4,s4 ,a ,book for the ,laboratories of ,colour ,works4 #hh pp4 ,crown #hvo4 ,price #es4 net4 7,post free1 #es4 #c;d4 home and abroad47 ,for contents of these books1 see ,list ,i4 ,,the ,,manufacture ,,and ,,comparative ,,merits ,,of ,,white ,,lead ,,and ,,zinc ,,white ,,paints4 ,by ,g4 ,,petit1 ,civil ,engineer1 etc4 ,translated from the ,french4 ,crown #hvo4 #ajj pp4 ,price #ds4 net4 7,post free1 #ds4 #c;d4 home2 #ds4 #d;d4 abroad47 ,,students' ,,handbook ,,of ,,paints1 ,,colours1 ,,oils ,,and ,,varnishes4 ,by ,,john ,,furnell4 ,crown #hvo4 #ab ,illustrations4 #if pp4 ,price #bs4 #f;d4 net4 7,post free1 #bs4 #i;d4 home and abroad47 7,varnishes and ,drying ,oils47 ,,the ,,manufacture ,,of ,,varnishes ,,and ,,kindred ,,industries4 ,by ,j4 ,,geddes ,,mcintosh4 ,second1 greatly enlarged1 ,english ,edition1 in three ,volumes1 based on and including the work of ,ach4 ,livache4 ,,volume ,i4--,,oil ,,crushing1 ,,refining ,,and ,,boiling1 ,,the ,,manufacture ,,of ,,linoleum1 ,,printing ,,and ,,lithographic ,,inks1 ,,and ,,india-,,rubber ,,substitutes4 ,demy #hvo4 #aej pp4 #bi ,illustrations4 ,price #gs4 #f;d4 net4 7,post free1 #gs4 #aj;d4 home2 #hs4 abroad47 ,,volume ,,ii4--,,varnish ,,materials ,,and ,,oil-,,varnish ,,making4 ,demy #hvo4 #gj ,illustrations4 #bbj pp4 ,price #ajs4 #f;d4 net4 7,post free1 #ajs4 #aj;d4 home2 #aas4 #c;d4 abroad47 ,,volume ,,iii4--,,spirit ,,varnishes ,,and ,,spirit ,,varnish ,,materials4 ,demy #hvo4 ,illustrated4 #dfd pp4 ,price #abs4 #f;d4 net4 7,post free1 #acs4 home2 #acs4 #f;d4 abroad47 ,,drying ,,oils1 ,,boiled ,,oil ,,and ,,solid ,,and ,,liquid ,,driers4 ,by ,l4,e4 ,,and,s4 ,expressly ,written for this ,series of ,special ,technical ,books1 and the ,publishers hold the ,copyright for ,english and ,foreign ,editions4 ,forty-two ,illustrations4 #cdb pp4 ,demy #hvo4 ,price #abs4 #f;d4 net4 7,post free1 #acs4 home2 #acs4 #c;d4 abroad47 7,analysis of ,resins1 see page #i47 7,oils1 ,fats1 ,waxes1 ,greases1 ,petroleum47 ,,lubricating ,,oils1 ,,pats ,,and ,,greases3 ,their ,origin1 ,preparation1 ,properties1 ,uses and ,analyses4 ,a ,handbook for ,oil ,manufacturers1 ,refiners and ,merchants1 and the ,oil and ,fat ,industry in ,general4 ,by ,,george ,h4 ,,hurst1 ,f4,c4,s4 ,third ,revised and ,enlarged ,edition4 ,seventy-four ,illustrations4 #chd pp4 ,demy #hvo4 ,price #ajs4 #f;d4 net4 7,post free1 #aas4 home2 #aas4 #c;d4 abroad47 ,,technology ,,of ,,petroleum3 ,oil ,fields of the ,world--,their ,history1 ,geography and ,geology--,annual ,production and ,development--,oil-well ,drilling--,transport4 ,by ,,henry ,,neuberger and ,,henry ,,noalhat4 ,translated from the ,french by ,j4,g4 ,,mcintosh4 #eej pp4 #aec ,illustrations4 #bf ,plates4 ,super ,royal #hvo4 ,price #bas4 net4 7,post free1 #bas1 #i;d4 home2 #bcs4 #f;d4 abroad47 ,,mineral ,,waxes3 ,their ,preparation and ,uses4 ,by ,,rudolf ,,gregorius4 ,translated from the ,german4 ,crown #hvo4 #bej pp4 #cb ,illustrations4 ,price #fs4 net4 7,post free1 #fs4 #d;d4 home2 #fs4 #f;d4 abroad47 ,,the ,,practical ,,compounding ,,of ,,oils1 ,,tallow ,,and ,,grease ,,for ,,lubrication1 ,,etc4 ,by ,an ,,expert ,,oil ,,refiner4 ,second ,edition4 #ajj pp4 ,demy #hvo4 ,price #gs4 #f;d4 net4 7,post free1 #gs4 #aj;d4 home2 #hs4 abroad47 ,,the ,,manufacture ,,of ,,lubricants1 ,,shoe ,,polishes ,,and ,,leather ,,dressings4 ,by ,,richard ,,brunner4 ,translated from the ,sixth ,german ,edition by ,,chas4 ,,salter4 #aj ,illustrations4 ,crown #hvo4 #agj pp4 ,price #gs4 #f;d4 net4 7,post free1 #gs4 #aj;d4 home2 #hs4 abroad47 ,,the ,,oil ,,merchants' ,,manual ,,and ,,oil ,,trade ,,ready ,,reckoner4 ,compiled by ,,frank ,f4 ,,sherriff4 ,second ,edition ,revised and ,enlarged4 ,demy #hvo4 #bad pp4 ,with ,two ,sheets of ,tables4 ,price #gs4 #f;d4 net4 7,post free1 #gs4 #aj;d4 home2 #hs4 #c;d4 abroad47 ,,animal ,,fats ,,and ,,oils3 ,their ,practical ,production1 ,purification and ,uses for a great ,variety of ,purposes4 ,their ,properties1 ,falsification and ,examination4 ,translated from the ,german of ,,louis ,,edgar ,,and,s4 ,sixty-two ,illustrations4 #bdj pp4 ,second ,edition1 ,revised and ,enlarged4 ,demy #hvo41 ,price #ajs4 #f;d4 net4 7,post free1 #ajs4 #aj;d4 home2 #aas4 #c;d4 abroad47 ,for contents of these books1 see ,list ,i4 ,,vegetable ,,fats ,,and ,,oils3 ,their ,practical ,preparation1 ,purification and ,employment for ,various ,purposes1 their ,properties1 ,adulteration and ,examination4 ,translated from the ,german of ,louis ,,edgar ,,and,s4 ,ninety-four ,illustrations4 #cdj pp4 ,second ,edition4 ,demy #hvo4 ,price #ajs4 #f;d4 net4 7,post free1 #aas4 home2 #aas4 #f;d4 abroad47 ,,edible ,,fats ,,and ,,oils3 ,their ,composition1 ,manufacture and ,analysis4 ,by ,w4,h4 ,,simmons1 ,b4,sc4 7,lond471 and ,c4,a4 ,,mitchell1 ,b4,a4 7,oxon474 ,demy #hvo4 #aej pp4 ,price #gs4 #f;d4 net4 7,post free1 #gs4 #i;d4 home2 #hs4 abroad47 7,essential ,oils and ,perfumes47 ,,the ,,chemistry ,,of ,,essential ,,oils ,,and ,,artificial ,,perfumes4 ,by ,,ernest ,j4 ,,parry1 ,b4,sc4 7,lond471 ,f4,i4,c41 ,f4,c4,s4 ,second ,edition1 ,revised and ,enlarged4 #eeb pp4 #bj ,illustrations4 ,demy #hvo4 ,price #abs4 #f;d4 net4 7,post free1 #acs4 home2 #acs4 #f;d4 abroad47 7,soap ,manufacture47 ,,soaps4 ,a ,practical ,manual of the ,manufacture of ,domestic1 ,toilet and other ,soaps4 ,by ,,george ,h4 ,,hurst1 ,f4,c4,s4 #bnd edition4 #cij pp4 #ff ,illustrations4 ,demy #hvo4 ,price #abs4 #f;d4 net4 7,post free1 #acs4 home2 #acs4 #f;d4 abroad47 ,,textile ,,soaps ,,and ,,oils4 ,handbook on the ,preparation1 ,properties and ,analysis of the ,soaps and ,oils used in ,textile ,manufacturing1 ,dyeing and ,printing4 ,by ,,george ,h4 ,,hurst1 ,f4,c4,s4 ,crown #hvo4 #aie pp4 #aijd4 ,price #es4 net4 7,post free1 #es4 #d;d4 home2 #es4 #f;d4 abroad47 ,,the ,,handbook ,,of ,,soap ,,manufacture4 ,by ,,wm4 ,h4 ,,simmons1 ,b4,sc4 7,lond471 ,f4,c4,s4 and ,h4,a4 ,,appleton4 ,demy #hvo4 #afj pp4 #bg ,illustrations4 ,price #hs4 #f;d4 net4 7,post free1 #hs4 #aj;d4 home2 #is4 abroad47 7,cosmetical ,preparations47 ,,cosmetics3 ,,manufacture1 ,,employment ,,and ,,testing ,,of ,,all ,,cosmetic ,,materials ,,and ,,cosmetic ,,specialities4 ,translated from the ,german of ,dr4 ,,theodor ,,koller4 ,crown #hvo4 #bfb pp4 ,price #es4 net4 7,post free1 #es4 #d;d4 home2 #es4 #f;d4 abroad47 7,glue1 ,bone ,products and ,manures47 ,,glue ,,and ,,glue ,,testing4 ,by ,,samuel ,,rideal1 ,d4,sc4 7,lond471 ,f4,i4,c4 ,fourteen ,engravings4 #add pp4 ,demy #hvo4 ,price #ajs4 #f;d4 net4 7,post free1 #ajs4 #aj;d4 home2 #aas4 abroad7 ,,bone ,,products ,,and ,,manures3 ,an ,account of the most recent ,improvements in the ,manufacture of ,fat1 ,glue1 ,animal ,charcoal1 ,size1 ,gelatine and ,manures4 ,by ,,thomas ,,lambert1 ,technical and ,consulting ,chemist4 ,illustrated by ,twenty-one ,plans and ,diagrams4 #afb pp4 ,demy #hvo4 ,price #gs4 #f;d4 net4 7,post free1 #gs4 #aj;d4 home2 #hs4 abroad47 7,see also ,chemical ,manures1 p4 #i47 7,chemicals1 ,waste ,products1 etc47 ,,reissue ,,of ,,chemical ,,essays ,,of ,c4,w4 ,,scheele4 ,first ,published in ,english in #aghf4 ,translated from the ,academy of ,sciences at ,stockholm1 with ,additions4 #cjj pp4 ,demy #hvo4 ,price #es4 net4 7,post free1 #es4 #f;d4 home2 #es4 #i;d4 abroad47 ,,the ,,manufacture ,,of ,,alum ,,and ,,the ,,sulphates ,,and ,,other ,,salts ,,of ,,alumina ,,and ,,iron4 ,their ,uses and ,applications as ,mordants in ,dyeing and ,calico ,printing1 and their other ,applications in the ,arts ,manufactures1 ,sanitary ,engineering1 ,agriculture and ,horticulture4 ,translated from the ,french of ,,lucien ,,geschwind4 #aie ,illustrations4 #djj pp4 ,royal #hvo4 ,price #abs4 #f;d4 net4 7,post free1 #acs4 home2 #acs4 #f;d4 abroad47 ,,ammonia ,,and ,,its ,,compounds3 ,their ,manufacture and ,uses4 ,by ,,camille ,,vincent1 ,professor at the ,central ,school of ,arts and ,manufactures1 ,paris4 ,translated from the ,french by ,m4,j4 ,,salter4 ,royal #hvo4 #aad pp4 ,thirty-two ,illustrations4 ,price #es4 net4 7,post free1 #es4 #d;d4 home2 #es4 #f;d4 abroad47 ,,chemical ,,works3 ,their ,design1 ,erection1 and ,equipment4 ,by ,s4,s4 ,,dyson and ,s4,s4 ,,clarkson4 ,royal #hvo4 #bbj pp4 ,with ,plates and ,illustrations4 ,price #bas4 net4 7,post free1 #bas4 #f;d4 home2 #bbs4 abroad47 ,,shale ,,tar ,,distillation3 ,the ,treatment of ,shale and ,lignite ,products4 ,translated from the ,german of ,w4 ,,scheithauer4 ,in the ,press4 ,for contents of these books1 see ,list ,i4 ,,industrial ,,alcohol4 ,a ,practical ,manual on the ,production and ,use of ,alcohol for ,industrial ,purposes and for ,use as a ,heating ,agent1 as an ,illuminant and as a ,source of ,motive ,power4 ,by ,j4,g4 ,,mcintosh1 ,lecturer on ,manufacture and ,applications of ,industrial ,alcohol at ,the ,polytechnic1 ,regent ,street1 ,london4 ,demy #hvo4 #aijg4 #bej pp4 ,with #ge ,illustrations and #be ,tables4 ,price #gs4 #f;d4 net4 7,post free1 #gs4 #i;d4 home2 #hs4 abroad47 ,,the ,,utilisation ,,of ,,waste ,,products4 ,a ,treatise on the ,rational ,utilisation1 ,recovery and ,treatment of ,waste ,products of all kinds4 ,by ,dr4 ,,theodor ,,koller4 ,translated from the ,second ,revised ,german ,edition4 ,twenty-two ,illustrations4 ,demy #hvo4 #bhj pp4 ,price #gs4 #f;d4 net4 7,post free1 #gs4 #aj;d4 home2 #hs4 #c;d4 abroad47 ,,analysis ,,of ,,resins ,,and ,,balsams4 ,translated from the ,german of ,dr4 ,,karl ,,dieterich4 ,demy #hvo4 #cdj pp4 ,price #gs4 #f;d4 net4 7,post free1 #gs4 #aj;d4 home2 #hs4 #c;d4 abroad47 7,agricultural ,chemistry and ,manures47 ,,manual ,,of ,,agricultural ,,chemistry4 ,by ,,herbert ,,ingle1 ,f4,i4,c41 ,late ,lecturer on ,agricultural ,chemistry1 the ,leeds ,university2 ,lecturer in the ,victoria ,university4 ,second ,edition1 with additional matter relating to ,tropical ,agriculture1 etc4 #dch pp4 #aa ,illustrations4 ,demy #hvo4 ,price #gs4 #f;d4 net4 7,post free1 #hs4 home2 #hs4 #f;d4 abroad47 ,,chemical ,,manures4 ,translated from the ,french of ,j4 ,,fritsch4 ,demy #hvo4 ,illustrated4 #cdj pp4 ,price #ajs4 #f;d4 net4 7,post free1 #aas4 home2 #aas4 #f;d4 abroad47 7,see also ,bone ,products and ,manures1 p4 #h47 7,writing ,inks and ,sealing ,waxes47 ,,ink ,,manufacture3 ,including ,writing1 ,copying1 ,lithographic1 ,marking1 ,stamping1 and ,laundry ,inks4 ,by ,,sigmund ,,lehner4 ,three ,illustrations4 ,crown #hvo4 #afb pp4 ,translated from the ,german of the ,fifth ,edition4 ,price #es4 net4 7,post free1 #es4 #c;d4 home2 #es4 #f;d4 abroad47 ,,sealing-,,waxes1 ,,wafers ,,and ,,other ,,adhesives ,,for ,,the ,,household1 ,,office1 ,,workshop ,,and ,,factory4 ,by ,h4,c4 ,,standage1 ,crown #hvo4 #if pp4 ,price #es4 net4 7,post free1 #es4 #c;d4 home2 #es4 #d;d4 abroad47 7,lead ,ores and ,lead ,compounds47 ,,lead ,,and ,,its ,,compounds4 ,by ,,thos4 ,,lambert1 ,technical and ,consulting ,chemist4 ,demy #hvo4 #bbf pp4 ,forty ,illustrations4 ,price #gs4 #f;d4 net4 7,post free1 #gs4 #aj;d4 home2 #hs4 #c;d4 abroad47 ,,notes ,,on ,,lead ,,ores3 ,their ,distribution and ,properties4 ,by ,,jas4 ,,fairie1 ,f4,g4,s4 ,crown #hvo4 #fd pages4 ,price #as4 net4 7,post free1 #as4 #c;d4 home2 #as4 #d;d4 abroad47 7,white ,lead and ,zinc ,white ,paints1 see p4 #e447 7,industrial ,hygiene47 ,,the ,,risks ,,and ,,dangers ,,to ,,health ,,of ,,various ,,occupations ,,and ,,their ,,prevention4 ,by ,,leonard ,a4 ,,parry1 ,m4,d41 ,b4,sc4 7,lond474 #aif pp4 ,demy #hvo4 ,price #gs4 #f;d4 net4 7,post free1 #gs4 #aj;d4 home2 #hs4 abroad47 7,industrial ,uses of ,air1 ,steam and ,water47 ,,drying ,,by ,,means ,,of ,,air ,,and ,,steam4 ,explanations1 ,formul1 and ,tables for ,use in ,practice4 ,translated from the ,german of ,e4 ,,hausbrand4 ,two folding ,diagrams and ,thirteen ,tables4 ,crown #hvo4 #gb pp4 ,price #es4 net4 7,post free1 #es4 #c;d4 home2 #es4 #f;d4 abroad47 7,see also ,evaporating1 ,condensing and ,cooling ,apparatus1 p4 #ai47 ,,pure ,,air1 ,,ozone1 ,,and ,,water4 ,a ,practical ,treatise of their ,utilisation and ,value in ,oil1 ,grease1 ,soap1 ,paint1 ,glue and other ,industries4 ,by ,w4,b4 ,,cowell4 ,twelve ,illustrations4 ,crown #hvo4 #he pp4 ,price #es4 net4 7,post free1 #es4 #c;d4 home2 #es4 #f;d4 abroad47 ,,the ,,industrial ,,uses ,,of ,,water4 ,,composition--,,effects--,,troubles--,, remedies--,,residuary ,,waters--,,purification--,,analysis4 ,by ,h4 ,,de ,,la ,,coux4 ,royal #hvo4 ,translated from the ,french and ,revised by ,,arthur ,,morris4 #cfd pp4 #ace ,illustrations4 ,price #ajs4 #f;d4 net4 7,post free1 #aas4 home2 #aas4 #f;d4 abroad47 7,see ,books on ,smoke ,prevention1 ,engineering and ,metallurgy1 p4 #ai1 etc47 ,for contents of these books1 see ,list ,,iii4 7,x ,rays47 ,,practical ,x ,,ray ,,work4 ,by ,,frank ,t4 ,,addyman1 ,b4,sc4 7,lond471 ,f4,i4,c41 ,member of the ,roentgen ,society of ,london2 ,radiographer to ,st4 ,george's ,hospital2 ,demonstrator of ,physics and ,chemistry1 and ,teacher of ,radiography in ,st4 ,george's ,hospital ,medical ,school4 ,demy #hvo4 ,twelve ,plates from ,photographs of ,x ,ray ,work4 ,fifty-two ,illustrations4 #bjj pp4 ,price #ajs4 #f;d4 net4 7,post free1 #ajs4 #aj;d4 home2 #aas4 #c;d4 abroad47 7,india-,rubber and ,gutta ,percha47 ,,india-,,rubber ,,and ,,gutta ,,percha4 ,second ,english ,edition1 ,revised and ,enlarged4 ,based on the ,french work of ,t4 ,,seeligmann1 ,g4 ,,lamy ,,torrilhon and ,h4 ,,falconnet by ,,john ,,geddes ,,mcintosh4 ,royal #hvo4 #ajj ,illustrations4 #djj pages4 ,price #abs4 #f;d4 net4 7,post free1 #acs4 home2 #acs4 #f;d4 abroad47 7,leather ,trades47 ,,the ,,leather ,,worker',s ,,manual4 ,being a ,compendium of ,practical ,recipes and ,working ,formul for ,curriers1 ,bootmakers1 ,leather ,dressers1 ,blacking ,manufacturers1 ,saddlers1 ,fancy ,leather ,workers4 ,by ,h4,c4 ,,standage4 ,demy #hvo4 #afe pp4 ,price #gs4 #f;d4 net4 7,post free1 #gs4 #aj;d4 home2 #hs4 abroad47 7,see also ,manufacture of ,shoe ,polishes1 ,leather ,dressings1 etc41 p4 #f47 7,pottery1 ,bricks1 ,tiles1 ,glass1 etc47 ,,modern ,,brickmaking4 ,by ,,alfred ,b4 ,,searle1 ,royal #hvo4 #ddj pages4 #bfj ,illustrations4 ,price #abs4 #f;d4 net4 7,post free1 #acs4 home2 #acs4 #f;d4 abroad47 ,,the ,,manual ,,of ,,practical ,,potting4 ,compiled by ,experts1 and ,edited by ,,chas4 ,f4 ,,binns4 ,third ,edition1 ,revised and ,enlarged4 #bjj pp4 ,demy #hvo4 ,price #ags4 #f;d4 net4 7,post free1 #ags4 #aj;d4 home2 #ahs4 #c;d4 abroad47 ,,pottery ,,decorating4 ,a ,description of all the ,processes for ,decorating ,pottery and ,porcelain4 ,by ,r4 ,,hainbach4 ,translated from the ,german4 ,crown #hvo4 #bej pp4 ,twenty-two ,illustrations4 ,price #gs4 #f;d4 net4 7,post free1 #gs4 #aj;d4 home2 #hs4 abroad47 ,a ,,treatise ,,on ,,ceramic ,,industries4 ,a ,complete ,manual for ,pottery1 ,tile1 and ,brick ,manufacturers4 ,by ,,emile ,,bourry4 ,a ,revised ,translation from the ,french1 with some ,critical ,notes by ,,alfred ,b4 ,,searle4 ,demy #hvo4 #cjh ,illustrations4 #dfj pp4 ,price #abs4 #f;d4 net4 7,post free1 #acs4 home2 #acs4 #f;d4 abroad47 ,,architectural ,,pottery4 ,bricks1 ,tiles1 ,pipes1 ,enamelled ,terra-cottas1 ,ordinary and ,incrusted ,quarries1 ,stoneware ,mosaics1 ,faences and ,architectural ,stoneware4 ,by ,,leon ,,lef,,vre4 ,translated from the ,french by ,k4,h4 ,,bird1 ,m4,a41 and ,w4 ,,moore ,,binns4 ,with ,five ,plates4 #iej ,illustrations in the ,text1 and numerous estimates4 #ejj pp41 royal #hvo4 ,price #aes4 net4 7,post free1 #aes4 #f;d4 home2 #afs4 #f;d4 abroad47 ,,ceramic ,,technology3 ,being some ,aspects of ,technical ,science as ,applied to ,pottery ,manufacture4 ,edited by ,,charles ,f4 ,,binns4 #ajj pp4 ,demy #hvo4 ,price #abs4 #f;d4 net4 7,post free1 #abs4 #aj;d4 home2 #acs4 abroad47 ,,the ,,art ,,of ,,riveting ,,glass1 ,,china ,,and ,,earthenware4 ,by ,j4 ,,howarth4 ,second ,edition4 ,paper ,cover4 ,price #as4 net4 7,by post1 home or abroad1 #as4 #a;d47 ,,notes ,,on ,,pottery ,,clays4 ,the ,distribution1 ,properties1 ,uses and ,analyses of ,ball ,clays1 ,china ,clays and ,china ,stone4 ,by ,,jas4 ,,fairie1 ,f4,g4,s4 #acb pp4 ,crown #hvo4 ,price #cs4 #f;d4 net4 7,post free1 #cs4 #i;d4 home2 #cs4 #aj;d4 abroad47 ,,how ,,to ,,analyse ,,clay4 ,by ,h4,m4 ,,ashby4 ,demy #hvo4 #gb ,pages4 #bj ,illustrations4 ,price #cs4 #f;d4 net4 7,post free1 #cs4 #i;d4 home2 #cs4 #aj;d4 abroad47 ,a ,reissue of ,,the ,,history ,,of ,,the ,,staffordshire ,,potteries2 ,,and ,,the ,,rise ,,and ,,progress ,,of ,,the ,,manufacture ,,of ,,pottery ,,and ,,porcelain4 ,with ,references to ,genuine ,specimens1 and ,notices of ,eminent ,potters4 ,by ,,simeon ,,shaw4 7,originally published in #ahbi47 #bfe pp4 ,demy #hvo4 ,price #es4 net4 7,post free1 #es4 #d;d4 home2 #es4 #i;d4 abroad47 ,a ,reissue of ,,the ,,chemistry ,,of ,,the ,,several ,,natural ,,and ,,artificial ,,heterogeneous ,,compounds ,,used ,,in ,,manufacturing ,,porcelain1 ,,glass ,,and ,,pottery4 ,by ,,simeon ,,shaw4 7,originally published in #ahcg47 #gej pp4 ,royal #hvo4 ,price #ajs4 net4 7,post free1 #ajs4 #f;d4 home2 #abs4 abroad47 ,,british ,,pottery ,,marks4 ,by ,g4 ,,woolliscroft ,,rhead4 ,demy #hvo4 #caj pp4 ,with over ,twelve-hundred ,illustrations of ,marks4 ,price #gs4 #f;d4 net4 7,post free1 #hs4 home2 #hs4 #c;d4 abroad47 ,for contents of these books1 see ,list ,,iii4 7,glassware1 ,glass ,staining and ,painting47 ,,recipes ,,for ,,flint ,,glass ,,making4 ,by a ,british ,glass ,master and ,mixer4 ,sixty ,recipes4 ,being ,leaves from the ,mixing ,book of several experts in the ,flint ,glass ,trade1 containing up-to-date recipes and valuable information as to ,crystal1 ,demi-crystal and ,coloured ,glass in its many varieties4 ,it contains the recipes for cheap metal suited to pressing1 blowing1 etc41 as well as the most costly crystal and ruby4 ,second ,edition4 ,crown #hvo4 ,price #ajs4 #f;d4 net4 7,post free1 #ajs4 #i;d4 home2 #ajs4 #aj;d4 abroad47 ,a ,,treatise ,,on ,,the ,,art ,,of ,,glass ,,painting4 ,prefaced with a ,review of ,ancient ,glass4 ,by ,,ernest ,r4 ,,suffling4 ,with ,one ,coloured ,plate and ,thirty-seven ,illustrations4 ,demy #hvo4 #adj pp4 ,price #gs4 #f;d4 net4 7,post free1 #gs4 #aj;d4 home2 #hs4 abroad47 7,paper ,making1 ,paper ,dyeing1 and ,testing47 ,,the ,,dyeing ,,of ,,paper ,,pulp4 ,a ,practical ,treatise for the use of ,papermakers1 ,paperstainers1 ,students and others4 ,by ,,julius ,,erfurt1 ,manager of a ,paper ,mill4 ,translated into ,english and ,edited with ,additions by ,,julius ,h,,bner1 ,f4,c4,s41 ,lecturer on ,papermaking at the ,manchester ,municipal ,technical ,school4 ,with illustrations and #aeg patterns of paper dyed in the pulp4 ,royal #hvo1 #ahj pp4 ,price #aes4 net4 7,post free1 #aes4 #f;d4 home2 #afs4 #f;d4 abroad74 ,,the ,,paper ,,mill ,,chemist4 ,by ,,henry ,p4 ,,stevens1 ,m4,a41 ,ph4,d41 ,f4,i4,c4 ,royal #abmo4 #fj illustrations4 #cjj pp4 ,price #gs4 #f;d4 net4 7,post free1 #gs4 #i;d4 home2 #gs4 #aj;d4 abroad47 ,,the ,,treatment ,,of ,,paper ,,for ,,special ,,purposes4 ,by ,l4,e4 ,,and,s4 ,translated from the ,german4 ,crown #hvo4 #dh ,illustrations4 #bej pp4 ,price #fs4 net4 7,post free1 #fs4 #d;d4 home2 #fs4 #f;d4 abroad47 7,enamelling on ,metal47 ,,enamels ,,and ,,enamelling4 ,for ,enamel ,makers1 ,workers in ,gold and ,silver1 and ,manufacturers of ,objects of ,art4 ,by ,,paul ,,randau4 ,translated from the ,german4 ,with ,sixteen ,illustrations4 ,demy #hvo4 #ahj pp4 ,price #ajs4 #f;d4 net4 7,post free1 #ajs4 #aj;d4 home2 #aas4 abroad47 ,,the ,,art ,,of ,,enamelling ,,on ,,metal4 ,by ,w4 ,,norman ,,brown4 ,twenty-eight ,illustrations4 ,crown #hvo4 #fj pp4 ,price #bs4 #f;d4 net4 7,post free1 #bs4 #i;d4 home and abroad47 7,textile and ,dyeing ,subjects47 ,,the ,,finishing ,,of ,,textile ,,fabrics 7,woollen1 ,worsted1 ,union and other ,cloths74 ,by ,,roberts ,,beaumont1 ,m4,sc41 ,m4,i4 ,mech4,e41 ,professor of ,textile ,industries1 the ,university of ,leeds2 ,author of ,colour in ,woven ,design2 ,woollen and ,worsted ,cloth ,manufacture2 ,woven ,fabrics at the ,world's ,fair2 ,vice-,president of the ,jury of ,award at the ,paris ,exhibition1 #aijj2 ,inspector of ,textile ,institutes2 ,society of ,arts ,silver ,medallist2 ,honorary ,medallist of the ,city and ,guilds of ,london ,institute4 ,with #aej ,illustrations of ,fibres1 ,yarns and ,fabrics1 also ,sectional and other ,drawings of ,finishing ,machinery ,demy #hvo4 #bfj pp4 ,price #ajs4 #f;d4 net4 7,post free1 #ajs4 #aj;d4 home2 #aas4 #c;d4 abroad47 ,,fibres ,,used ,,in ,,textile ,,and ,,allied ,,industries4 ,by ,c4 ,,ainsworth ,,mitchell1 ,b4,a4 7,oxon471 ,f4,i4,c41 and ,r4,m4 ,,prideaux1 ,f4,i4,c4 ,with #ff ,illustrations specially drawn direct from the ,fibres4 ,demy #hvo4 #bjj pp4 ,price #gs4 #f;d4 net4 7,post free1 #gs4 #aj;d4 home2 #hs4 abroad47 ,,dressings ,,and ,,finishings ,,for ,,textile ,,fabrics ,,and ,,their ,,application4 ,description of all the ,materials used in ,dressing ,textiles3 ,their ,special ,properties1 the preparation of ,dressings and their employment in ,finishing ,linen1 ,cotton1 ,woollen and ,silk ,fabrics4 ,fireproof and ,waterproof ,dressings1 together with the principal machinery employed4 ,translated from the ,third ,german ,edition of ,,friedrich ,,polleyn4 ,demy #hvo4 #bhj pp4 ,sixty ,illustrations4 ,price #gs4 #f;d4 net4 7,post free1 #gs4 #aj;d4 home2 #hs4 abroad47 ,,the ,,chemical ,,technology ,,of ,,textile ,,fibres2 ,their ,origin1 ,structure1 ,preparation1 ,washing1 ,bleaching1 ,dyeing1 ,printing and ,dressing4 ,by ,dr4 ,,georg ,,von ,,georgievics4 ,translated from the ,german by ,,charles ,,salter4 #cbj pp4 ,forty-seven ,illustrations4 ,royal #hvo4 ,price #ajs4 #f;d4 net4 7,post free1 #aas4 home2 #aas4 #c;d4 abroad47 ,,power-,,loom ,,weaving ,,and ,,yarn ,,numbering1 ,according to ,various ,systems1 with ,conversion ,tables4 ,translated from the ,german of ,,anthon ,,gruner4 ,with ,twenty-six ,diagrams in ,colours4 #aej pp4 ,crown #hvo4 ,price #gs4 #f;d4 net4 7,post free1 #gs4 #i;d4 home2 #hs4 abroad47 ,,textile ,,raw ,,materials ,,and ,,their ,,conversion ,,into ,,yarns4 7,the ,study of the ,raw ,materials and the ,technology of the ,spinning ,process47 ,by ,,julius ,,zipser4 ,translated from ,german by ,,charles ,,salter4 #cjb ,illustrations4 #ejj pp4 ,demy #hvo4 ,price #ajs4 #f;d4 net4 7,post free1 #aas4 home2 #aas4 #f;d4 abroad47 ,for contents of these books1 see ,list ,,ii4 ,,grammar ,,of ,,textile ,,design4 ,by ,h4 ,,nisbet1 ,weaving and ,designing ,master1 ,bolton ,municipal ,technical ,school4 ,demy #hvo4 #bhj pp4 #dij ,illustrations and ,diagrams4 ,price #fs4 net4 7,post free1 #fs4 #d;d4 home2 #fs4 #f;d4 abroad47 ,,art ,,needlework ,,and ,,design4 ,,point ,,lace4 ,a ,manual of ,applied ,art for ,secondary ,schools and ,continuation ,classes4 ,by ,m4,e4 ,,wilkinson4 ,oblong quarto4 ,with #bb ,plates4 ,bound in ,art ,linen4 ,price #cs4 #f;d4 net4 7,post free1 #cs4 #aj;d4 home2 #ds4 abroad47 ,,home ,,lace-,,making4 ,a ,handbook for ,teachers and ,pupils4 ,by ,m4,e4,w4 ,,milroy4 ,crown #hvo4 #fd pp4 ,with #c ,plates and #i ,diagrams4 ,price #as4 net4 7,post free1 #as4 #c;d4 home2 #as4 #d;d4 abroad47 ,,the ,,chemistry ,,of ,,hat ,,manufacturing4 ,lectures delivered before the ,hat ,manufacturers' ,association4 ,by ,,watson ,,smith1 ,f4,c4,s41 ,f4,i4,c4 ,revised and ,edited by ,,albert ,,shonk4 ,crown #hvo4 #acb pp4 #af ,illustrations4 ,price #gs4 #f;d4 net4 7,post free1 #gs4 #i;d4 home2 #gs4 #aj;d4 abroad47 ,,the ,,technical ,,testing ,,of ,,yarns ,,and ,,textile ,,fabrics4 ,with ,reference to ,official ,specifications4 ,translated from the ,german of ,dr4 ,j4 ,,herzfeld4 ,second ,edition4 ,sixty-nine ,illustrations4 #bjj pp4 ,demy #hvo4 ,price #ajs4 #f;d4 net4 7,post free1 #ajs4 #aj;d4 home2 #aas4 abroad47 ,,decorative ,,and ,,fancy ,,textile ,,fabrics4 ,by ,r4,t4 ,,lord4 ,for ,manufacturers and ,designers of ,carpets1 ,damask1 ,dress and all ,textile ,fabrics4 #bjj pp4 ,demy #hvo4 #acb ,designs and ,illustrations4 ,price #gs4 #f;d4 net4 7,post free1 #gs4 #aj;d4 home2 #hs4 abroad47 ,,theory ,,and ,,practice ,,of ,,damask ,,weaving4 ,by ,h4 ,,kinzer and ,k4 ,,walter4 ,royal #hvo4 ,eighteen ,folding ,plates4 ,six ,illustrations4 ,translated from the ,german4 #aaj pp4 ,price #hs4 #f;d4 net4 7,post free1 #is4 home2 #is4 #f;d4 abroad47 ,,faults ,,in ,,the ,,manufacture ,,of ,,woollen ,,goods ,,and ,,their ,,prevention4 ,by ,,nicolas ,,reiser4 ,translated from the ,second ,german ,edition4 ,crown #hvo4 ,sixty-three ,illustrations4 #agj pp4 ,price #es4 net4 7,post free1 #es4 #d;d4 home2 #es4 #f;d4 abroad47 ,,spinning ,,and ,,weaving ,,calculations1 especially relating to ,woollens4 ,from the ,german of ,n4 ,,reiser4 ,thirty-four ,illustrations4 ,tables4 #afj pp4 ,demy #hvo4 #aijd4 ,price #ajs4 #f;d4 net4 7,post free1 #ajs4 #aj;d4 home2 #aas4 abroad47 ,,waterproofing ,,of ,,fabrics4 ,by ,dr4 ,s4 ,,mierzinski4 ,crown #hvo4 #ajd pp4 #bi ,illus4 ,price #es4 net4 7,post free1 #es4 #c;d4 home2 #es4 #d;d4 abroad47 ,,how ,,to ,,make ,a ,,woollen ,,mill ,,pay4 ,by ,,john ,,mackie4 ,crown #hvo4 #gf pp4 ,price #cs4 #f;d4 net4 7,post free1 #cs4 #i;d4 home2 #cs4 #aj;d4 abroad47 ,,yarn ,,and ,,warp ,,sizing ,,in ,,all ,,its ,,branches4 ,translated from the ,german of ,,carl ,,kretschmar4 ,royal #hvo4 #abc ,illustrations4 #aej pp4 ,price #ajs4 #f;d4 net4 7,post free1 #ajs4 #aj;d4 home2 #aas4 abroad47 7,for ,textile ,soaps and ,oils see p4 #g47 7,dyeing1 ,colour ,printing1 ,matching and ,dye-stuffs47 ,,the ,,colour ,,printing ,,of ,,carpet ,,yarns4 ,manual for ,colour ,chemists and ,textile ,printers4 ,by ,,david ,,paterson1 ,f4,c4,s4 ,seventeen ,illustrations4 #acf pp4 ,demy #hvo4 ,price #gs4 #f;d4 net4 7,post free1 #gs4 #aj;d4 home2 #hs4 abroad47 ,,the ,,science ,,of ,,colour ,,mixing4 ,a ,manual intended for the use of ,dyers1 ,calico ,printers and ,colour ,chemists4 ,by ,,david ,,paterson1 ,f4,c4,s4 ,forty-one ,illustrations4 ,five ,coloured ,plates1 and ,four ,plates showing ,eleven ,dyed ,specimens ,of ,fabrics4 #acb pp4 ,demy #hvo4 ,price #gs4 #f;d4 net4 7,post free1 #gs4 #aj;d4 home2 #hs4 abroad47 ,,dyers' ,,materials3 ,an ,introduction to the ,examination1 ,evaluation and ,application of the most important ,substances used in ,dyeing1 ,printing1 ,bleaching and ,finishing4 ,by ,,paul ,,heerman1 ,ph4,d4 ,translated from the ,german by ,a4,c4 ,,wright1 ,m4,a4 7,oxon741 ,b4,sc4 7,lond474 ,twenty-four ,illustrations4 ,crown #hvo4 #aej pp4 ,price #es4 net4 7,post free1 #es4 #d;d4 home2 #es4 #f;d4 abroad47 ,,colour ,,matching ,,on ,,textiles4 ,a ,manual intended for the use of ,students of ,colour ,chemistry1 ,dyeing and ,textile ,printing4 ,by ,,david ,,paterson1 ,f4,c4,s4 ,coloured ,frontispiece4 ,twenty-nine ,illustrations and ,fourteen ,specimens of ,dyed ,fabrics4 ,demy #hvo4 #acb pp4 ,price #gs4 #f;d4 net4 7,post free1 #gs4 #aj;d4 home2 #hs4 abroad47 ,,colour3 ,a ,,handbook ,,of ,,the ,,theory ,,of ,,colour4 ,by ,,george ,h4 ,,hurst1 ,f4,c4,s4 ,with ,ten ,coloured ,plates and ,seventy-two ,illustrations4 #afj pp4 ,demy #hvo4 ,price #gs4 #f;d4 net4 7,post free1 #gs4 #aj;d4 home2 #hs4 abroad47 ,for contents of these books1 see ,list ,,ii4 ,reissue of ,,the ,,art ,,of ,,dyeing ,,wool1 ,,silk ,,and ,,cotton4 ,translated from the ,french of ,m4 ,,hellot1 ,m4 ,,macquer and ,m4 ,,le ,,pileur ,d',,apligny4 ,first ,published in ,english in #aghi4 ,six ,plates4 ,demy #hvo4 #ddf pp4 ,price #es4 net4 7,post free1 #es4 #f;d4 home2 #fs4 abroad47 ,,the ,,chemistry ,,of ,,dye-,,stuffs4 ,by ,dr4 ,,georg ,,von ,,georgievics4 ,translated from the ,second ,german ,edition4 #dab pp4 ,demy #hvo4 ,price #ajs4 #f;d4 net4 7,post free1 #aas4 home2 #aas4 #f;d4 abroad47 ,,the ,,dyeing ,,of ,,cotton ,,fabrics3 ,a ,practical ,handbook for the ,dyer and ,student4 ,by ,,franklin ,,beech1 ,practical ,colourist and ,chemist4 #bgb pp4 ,forty-four ,illustrations of ,bleaching and ,dyeing ,machinery4 ,demy #hvo4 ,price #gs4 #f;d4 net4 7,post free1 #gs4 #aj;d4 home2 #hs4 abroad47 ,,the ,,dyeing ,,of ,,woollen ,,fabrics4 ,by ,,franklin ,,beech1 ,practical ,colourist and ,chemist4 ,thirty-three ,illustrations4 ,demy #hvo4 #bbh pp4 ,price #gs4 #f;d4 net4 7,post free1 #gs4 #aj;d4 home2 #hs4 abroad47 7,silk ,manufacture47 ,,silk ,,throwing ,,and ,,waste ,,silk ,,spinning4 ,by ,,hollins ,,rayner4 ,demy #hvo4 #agj pp4 #aag ,illus4 ,price #es4 net4 7,post free1 #es4 #d;d4 home2 #es4 #f;d4 abroad47 7,bleaching and ,bleaching ,agents47 ,a ,,practical ,,treatise ,,on ,,the ,,bleaching ,,of ,,linen ,,and ,,cotton ,,yarn ,,and ,,fabrics4 ,by ,l4 ,,tailfer1 ,chemical and ,mechanical ,engineer4 ,translated from the ,french by ,,john ,,geddes ,,mcintosh4 ,demy #hvo4 #cjc pp4 ,twenty ,illus4 ,price #abs4 #f;d4 net4 7,post free1 #acs4 home2 #acs4 #f;d4 abroad47 ,,modern ,,bleaching ,,agents ,,and ,,detergents4 ,by ,professor ,,max ,,bottler4 ,translated from the ,german4 ,crown #hvo4 #af ,illustrations4 #afj pages4 ,price #es4 net4 7,post free1 #es4 #c;d4 home2 #es4 #f;d4 abroad47 7,cotton ,spinning and ,combing47 ,,cotton ,,spinning 7,first ,year74 ,by ,,thomas ,,thornley1 ,spinning ,master1 ,bolton ,technical ,school4 #afj pp4 ,eighty-four ,illustrations4 ,crown #hvo4 ,second ,impression4 ,price #cs4 net4 7,post free1 #cs4 #d;d4 home2 #cs4 #f;d4 abroad47 ,,cotton ,,spinning 7,intermediate1 or ,second ,year74 ,by ,,thomas ,,thornley4 ,second ,impression4 #ahj pp4 ,seventy ,illustrations4 ,crown #hvo4 ,price #es4 net4 7,post free1 #es4 #d;d4 home3 #es4 #f;d4 abroad47 ,,cotton ,,spinning 7,honours1 or ,third ,year74 ,by ,,thomas ,,thornley4 #baf pp ,seventy-four ,illustrations4 ,crown #hvo4 ,second ,edition4 ,price #es4 net4 7,post free1 #es4 #d;d4 home2 #es4 #f;d4 abroad47 ,,cotton ,,combing ,,machines4 ,by ,,thos4 ,,thornley1 ,spinning ,master1 ,technical ,school1 ,bolton4 ,demy #hvo4 #aag ,illustrations4 #cjj pp4 ,price #gs4 #f;d4 net4 7,post free1 #hs4 home2 #hs4 #f;d4 abroad47 ,,cotton ,,waste3 ,its ,production1 ,characteristics1 ,regulation1 ,opening1 ,carding1 ,spinning and ,weaving4 ,by ,,thomas ,,thornley4 ,demy #hvo4 ,about #cjj pages4 ,in the press4 ,,the ,,ring ,,spinning ,,frame3 ,,guide ,,for ,,overlookers ,,and ,,students4 ,by ,n4 ,,booth4 ,crown #hvo4 #gf pages4 ,price #cs4 net4 7,post free1 #cs4 #c;d4 home2 #cs4 #f;d4 abroad47 ,just published4 7,flax1 ,hemp and ,jute ,spinning47 ,,modern ,,flax1 ,,hemp ,,and ,,jute ,,spinning ,,and ,,twisting4 ,a ,practical ,handbook for the use of ,flax1 ,hemp and ,jute ,spinners1 ,thread1 ,twine and ,rope ,makers4 ,by ,,herbert ,r4 ,,carter1 ,mill ,manager1 ,textile ,expert and ,engineer1 ,examiner in ,flax ,spinning to the ,city and ,guilds of ,london ,institute4 ,demy #hvo4 #aijg4 ,with #ib ,illustrations4 #bjj pp4 ,price #gs4 #f;d4 net4 7,post free1 #gs4 #i;d4 home2 #hs abroad47 7,collieries and ,mines47 ,,recovery ,,work ,,after ,,pit ,,fires4 ,by ,,robert ,,lamprecht1 ,mining ,engineer and ,manager4 ,translated from the ,german4 ,illustrated by ,six large ,plates1 containing ,seventy-six ,illustrations4 #age pp4 ,demy #hvo4 ,price #ajs4 #f;d4 net4 7,post free1 #ajs4 #aj;d4 home2 #aas4 abroad47 ,,ventilation ,,in ,,mines4 ,by ,,robert ,,wabner1 ,mining ,engineer4 ,translated from the ,german4 ,royal #hvo4 ,thirty ,plates and ,twenty-two ,illustrations4 #bdj pp4 ,price #ajs4 #f;d4 net4 7,post free1 #aas4 home2 #aas4 #c;d4 abroad47 ,,haulage ,,and ,,winding ,,appliances ,,used ,,in ,,mines4 ,by ,,carl ,,volk4 ,translated from the ,german4 ,royal #hvo4 ,with ,six ,plates and #adh ,illustrations4 #aej pp4 ,price #hs4 #f;d4 net4 7,post free1 #is4 home2 #is4 #c;d4 abroad47 ,for contents of these books1 see ,list ,,iii4 ,,the ,,electrical ,,equipment ,,of ,,collieries4 ,by ,w4 ,,galloway ,,duncan1 ,electrical and ,mechanical ,engineer1 ,member of the ,institution of ,mining ,engineers1 ,head of the ,government ,school of ,engineering1 ,dacca1 ,india2 and ,,david ,,penman1 ,certificated ,colliery ,manager1 ,lecturer in ,mining to ,fife ,county ,committee4 ,demy #hvo4 #caj pp4 #aee ,illustrations and ,diagrams4 ,price #ajs4 #f;d4 net4 7,post free1 #aas4 home2 #aas4 #c;d4 abroad47 7,dental ,metallurgy47 ,,dental ,,metallurgy3 ,,manual ,,for ,,students ,,and ,,dentists4 ,by ,a4,b4 ,,griffiths1 ,ph4,d4 ,demy #hvo4 ,thirty-six ,illustrations4 #bjj pp4 ,price #gs4 #f;d4 net4 7,post free1 #gs4 #aj;d4 home2 #hs4 abroad47 7,engineering1 ,smoke ,prevention and ,metallurgy47 ,,the ,,prevention ,,of ,,smoke4 ,combined with the ,economical ,combustion of ,fuel4 ,by ,w4,c4 ,,popplewell1 ,m4,sc41 ,a4,m4 ,inst41 ,c4,e41 ,consulting ,engineer4 ,forty-six ,illustrations4 #aij pp4 ,demy #hvo4 ,price #gs4 #f;d4 net4 7,post free1 #gs4 #aj;d4 home2 #hs4 #c;d4 abroad47 ,,gas ,,and ,,coal ,,dust ,,firing4 ,a ,critical ,review of the ,various ,appliances ,patented in ,germany for this purpose since #ahhe4 ,by ,,albert ,p,,tsch4 #acj pp4 ,demy #hvo4 ,translated from the ,german4 ,with #ajc ,illustrations4 ,price #es4 net4 7,post free1 #es4 #d;d4 home2 #es4 #f;d4 abroad47 ,,the ,,hardening ,,and ,,tempering ,,of ,,steel ,,in ,,theory ,,and ,,practice4 ,by ,,fridolin ,,reiser4 ,translated from the ,german of the ,third ,edition4 ,crown #hvo4 #abj pp4 ,price #es4 net4 7,post free1 #es4 #c;d4 home2 #es4 #d;d4 abroad47 ,,siderology3 ,,the ,,science ,,of ,,iron 7,the ,constitution of ,iron ,alloys and ,slags74 ,translated from ,german of ,,hanns ,,freiherr ,v4 ,j,,ptner4 #cej pp4 ,demy #hvo4 ,eleven ,plates and ,ten ,illustrations4 ,price #ajs4 #f;d4 net4 7,post free1 #aas4 home2 #aas4 #f;d4 abroad47 ,,evaporating1 ,,condensing ,,and ,,cooling ,,apparatus4 ,explanations1 ,formul and ,tables for ,use in ,practice4 ,by ,e4 ,,hausbrand1 ,engineer4 ,translated by ,a4,c4 ,,wright1 ,m4,a4 7,oxon471 ,b4,sc41 7,lond474 ,with ,twenty-one ,illustrations and ,seventy-six ,tables4 #djj pp4 ,demy #hvo4 ,price #ajs4 #f;d4 net4 7,post free1 #aas4 home2 #aas4 #f;d4 abroad47 7,the ,broadway ,series of ,engineering ,handbooks47 ,,volume ,i4--,,reinforced ,,concrete4 ,by ,,ewart ,s4 ,,andrews1 ,b4,sc4 ,eng4 7,lond474 ,in the press4 ,,volume ,,ii4--,,gas ,,and ,,oil ,,engines4 ,in the press4 ,,volume ,,iii4--,,structural ,,steel ,,and ,,iron ,,work4 ,in the press4 ,,volume ,,iv4--,,toothed ,,gearing4 ,by ,g4,t4 ,,white1 ,b4,sc4 7,lond474 ,in the press4 ,,volume ,v4--,,steam ,,turbines3 ,their ,theory and ,construction4 ,in the press4 7,sanitary ,plumbing1 ,electric ,wiring1 ,metal ,work1 etc47 ,,external ,,plumbing ,,work4 ,a ,treatise on ,lead ,work for ,roofs4 ,by ,,john ,w4 ,,hart1 ,r4,p4,c4 #ahj ,illustrations4 #bgb pp4 ,demy #hvo4 ,second ,edition ,revised4 ,price #gs4 #f;d4 net4 7,post free4 #gs4 #aj;d4 home2 #hs4 abroad47 ,,hints ,,to ,,plumbers ,,on ,,joint ,,wiping1 ,,pipe ,,bending ,,and ,,lead ,,burning4 ,third ,edition1 ,revised and ,corrected1 ,by ,,john ,w4 ,,hart1 ,r4,p4,c4 #ahd ,illustrations4 #cac pp4 ,demy #hvo4 ,price #gs4 #f;d4 net4 7,post free1 #hs4 home2 #hs4 #f;d4 abroad47 ,,sanitary ,,plumbing ,,and ,,drainage4 ,by ,,john ,w4 ,,hart4 ,demy #hvo4 ,with #bjh ,illustrations4 #bej pp4 #aijd4 ,price #gs4 #f;d4 net4 7,post free1 #gs4 #aj;d4 home2 #hs4 abroad47 ,,electric ,,wiring ,,and ,,fitting4 ,by ,,sydney ,f4 ,,walker1 ,r4,n41 ,m4,i4,e4,e41 ,m4,i4,min4,e41 ,a4,m4,inst4,c4,e41 etc41 etc4 ,crown #hvo4 #aej pp4 ,with ,illustrations and ,tables4 ,price #es4 net4 7,post free1 #es4 #c;d4 home2 #es4 #f;d4 abroad47 ,,the ,,principles ,,and ,,practice ,,of ,,dipping1 ,,burnishing1 ,,lacquering ,,and ,,bronzing ,,brass ,,ware4 ,by ,w4 ,,norman ,,brown4 #dh pp4 ,crown #hvo4 ,price #cs4 net4 7,post free1 #cs4 #c;d4 home and abroad47 ,just published4 ,,the ,,development ,,of ,,the ,,incandescent ,,electric ,,lamps4 ,by ,g4 ,,basil ,,barham1 ,a4,m4,i4,e4,e4 ,illustrated4 ,demy #hvo4 #aif pp4 ,in the press4 ,for contents of these books1 see ,list ,i4 ,,wiring ,,calculations ,,for ,,electric ,,light ,,and ,,power ,,installations4 ,a ,practical ,handbook containing ,wiring ,tables1 ,rules1 and ,formul for the ,use of ,architects1 ,engineers1 ,mining ,engineers1 and ,electricians1 ,wiring ,contractors and ,wiremen1 etc4 ,by ,g4 ,,lummis ,,paterson4 ,crown #hvo4 ,twenty-two ,illustrations4 #ajj pp4 ,in the press4 ,a ,,handbook ,,on ,,japanning ,,and ,,enamelling ,,for ,,cycles1 ,,bedsteads1 ,,tinware1 ,,etc4 ,by ,,william ,,norman ,,brown4 #eb pp4 and ,illustrations4 ,crown #hvo4 ,price #bs4 net4 7,post free1 #bs4 #c;d4 home and abroad47 ,,the ,,principles ,,of ,,hot ,,water ,,supply4 ,by ,,john ,w4 ,,hart1 ,r4,p4,c4 ,with #abi ,illustrations4 #agg pp4 ,demy #hvo4 ,price #gs4 #f;d4 net4 7,post free1 #gs4 #aj;d4 home2 #hs4 abroad47 7,brewing and ,botanical47 ,,hops ,,in ,,their ,,botanical1 ,,agricultural ,,and ,,technical ,,aspect1 ,,and ,,as ,,an ,,article ,,of ,,commerce4 ,by ,,emmanuel ,,gross1 ,professor at the ,higher ,agricultural ,college1 ,tetschen-,liebwerd4 ,translated from the ,german4 ,seventy-eight ,illustrations4 #cdj pp4 ,demy #hvo4 ,price #ajs4 #f;d4 net4 7,post free1 #aas4 home2 #aas #f;d4 abroad47 ,a ,,book ,,on ,,the ,,diseases ,,of ,,plants1 ,,fungicides ,,and ,,insecticides1 ,,etc4 ,demy #hvo4 ,about #ejj pp4 ,in the press4 7,wood ,products1 ,timber and ,wood ,waste47 ,,wood ,,products3 ,,distillates ,,and ,,extracts4 ,by ,p4 ,,dumesny1 ,chemical ,engineer1 ,expert before the ,lyons ,commercial ,tribunal1 ,member of the ,international ,association of ,leather ,chemists2 and ,j4 ,,noyer4 ,translated from the ,french by ,,donald ,,grant4 ,royal #hvo4 #cbj pp4 #ajc ,illustrations and ,numerous ,tables4 ,price #ajs4 #f;d4 net4 7,post free1 #aas4 home2 #aas4 #f;d4 abroad47 ,,timber3 ,a ,comprehensive ,study of ,wood in all its ,aspects 7,commercial and ,botanical71 showing the different ,applications and ,uses of ,timber in ,various ,trades1 etc4 ,translated from the ,french of ,,paul ,,charpentier4 ,royal #hvo4 #dcg pp4 #agh ,illustrations4 ,price #abs4 #f;d4 net4 7,post free1 #acs4 home2 #ads4 abroad47 ,,the ,,utilisation ,,of ,,wood ,,waste4 ,translated from the ,german of ,,ernst ,,hubbard4 ,crown #hvo4 #aib pp4 ,fifty ,illustrations4 ,price #es4 net4 7,post free1 #es4 #d;d4 home2 #es4 #f;d4 abroad47 7,see also ,utilisation of ,waste ,products1 p4 #i47 7,building and ,architecture47 ,,ornamental ,,cement ,,work4 ,by ,,oliver ,,wheatley4 ,demy #hvo4 #hc ,illustrations4 #abh pp4 ,price #es4 net4 7,post free1 #es4 #d;d4 home2 #es4 #f;d4 abroad47 ,just published4 ,,the ,,prevention ,,of ,,dampness ,,in ,,buildings2 with ,remarks on the ,causes1 ,nature and ,effects of ,saline1 ,efflorescences and ,dry-rot1 for ,architects1 ,builders1 ,overseers1 ,plasterers1 ,painters and ,house ,owners4 ,by ,,adolf ,,wilhelm ,,keim4 ,translated from the ,german of the second revised ,edition by ,m4,j4 ,,salter1 ,f4,i4,c41 ,f4,c4,s4 ,eight ,coloured ,plates and ,thirteen ,illustrations4 ,crown #hvo4 #aae pp4 ,price #es4 net4 7,post free1 #es4 #c;d4 home2 #es4 #d;d4 abroad47 ,,handbook ,,of ,,technical ,,terms ,,used ,,in ,,architecture ,,and ,,building1 ,,and ,,their ,,allied ,,trades ,,and ,,subjects4 ,by ,,augustine ,c4 ,,passmore4 ,demy #hvo4 #chj pp4 ,price #gs4 #f;d4 net4 7,post free1 #hs4 home2 #hs4 #f;d4 abroad47 7,foods1 ,drugs and ,sweetmeats47 ,,food ,,and ,,drugs4 ,by ,e4,j4 ,,parry1 ,b4,sc41 ,f4,i4,c41 ,f4,c4,s4 ,volume ,i4 ,the ,analysis of ,food and ,drugs 7,chemical and ,microscopical74 ,royal #hvo4 #gbd pp4 ,price #bas4 net4 7,post free1 #bas4 #h;d4 home2 #bbs4 abroad47 ,volume ,,ii4 ,the ,sale of ,food and ,drugs ,acts1 #ahge-aijg4 ,royal #hvo4 #ahd pp4 ,price #gs4 #f;d4 net4 7,post free1 #gs4 #aj;d4 home2 #hs4 abroad47 ,just published4 ,,the ,,manufacture ,,of ,,preserved ,,foods ,,and ,,sweetmeats4 ,by ,a4 ,,hausner4 ,with ,twenty-eight ,illustrations4 ,translated from the ,german of the third enlarged ,edition4 ,crown #hvo4 #bbe pp4 ,price #gs4 #f;d4 net4 7,post free1 #gs4 #i;d4 home2 #gs4 #aj;d4 abroad47 ,,recipes ,,for ,,the ,,preserving ,,of ,,fruit1 ,,vegetables ,,and ,,meat4 ,by ,e4 ,,wagner4 ,translated from the ,german4 ,crown #hvo4 #abe pp4 ,with #ad ,illustrations4 ,price #es4 net4 7,post free1 #es4 #c;d4 home2 #es4 #d;d4 abroad47 ,for contents of these books1 see ,list ,,iii4 7,dyeing ,fancy ,goods47 ,,the ,,art ,,of ,,dyeing ,,and ,,staining ,,marble1 ,,artificial ,,stone1 ,,bone1 ,,horn1 ,,ivory ,,and ,,wood1 ,,and ,,of ,,imitating ,,all ,,sorts ,,of ,,wood4 ,a ,practical ,handbook for the ,use of ,joiners1 ,turners1 ,manufacturers of ,fancy ,goods1 ,stick and ,umbrella ,makers1 ,comb ,makers1 etc4 ,translated from the ,german of ,d4,h4 ,,soxhlet1 ,technical ,chemist4 ,crown #hvo4 #afh pp4 ,price #es4 net4 7,post free1 #es4 #c;d4 home2 #es4 #d;d4 abroad47 7,celluloid47 ,,celluloid3 ,its ,raw ,material1 ,manufacture1 ,properties and ,uses4 ,a ,handbook for ,manufacturers of ,celluloid and ,celluloid ,articles1 and all ,industries using ,celluloid2 also for ,dentists and ,teeth ,specialists4 ,by ,dr4 ,fr4 ,b,,ckmann1 ,technical ,chemist4 ,translated from the ,third ,revised ,german ,edition4 ,crown #hvo4 #abj pp4 ,with #di ,illustrations4 ,price #es4 net4 7,post free1 #es4 #c;d4 home2 #es4 #d;d4 abroad47 7,lithography1 ,printing and ,engraving47 ,,practical ,,lithography4 ,by ,,alfred ,,seymour4 ,demy #hvo4 ,with ,frontispiece and #cc ,illus4 #abj pp4 ,price #es4 net4 7,post free1 #es4 #d;d4 home2 #es4 #f;d4 abroad47 ,,printers' ,,and ,,stationers' ,,ready ,,reckoner ,,and ,,compendium4 ,compiled by ,,victor ,,graham4 ,crown #hvo4 #aab pp4 #aijd4 ,price #cs4 #f;d4 net4 7,post free1 #cs4 #i;d4 home2 #cs4 #aj;d4 abroad47 ,,engraving ,,for ,,illustration4 ,,historical ,,and ,,practical ,,notes4 ,by ,j4 ,,kirkbride4 #gb pp4 ,two ,plates and #f ,illustrations4 ,crown #hvo4 ,price #bs4 #f;d4 net4 7,post free1 #bs4 #i;d4 home2 #bs4 #aj;d4 abroad47 7,for ,printing ,inks1 see p4 #d47 7,bookbinding47 ,,practical ,,bookbinding4 ,by ,,paul ,,adam4 ,translated from the ,german4 ,crown #hvo4 #ahj pp4 #abg ,illustrations4 ,price #es4 net4 7,post free1 #es4 #d;d4 home2 #es4 #f;d4 abroad47 7,sugar ,refining47 ,,the ,,technology ,,of ,,sugar3 ,practical ,treatise on the ,modern ,methods of ,manufacture of ,sugar from the ,sugar ,cane and ,sugar ,beet4 ,by ,,john ,,geddes ,,mcintosh4 ,second ,revised and ,enlarged ,edition4 ,demy #hvo4 ,fully ,illustrated4 #dcf pp4 ,seventy-six ,tables4 #aijf4 ,price #ajs4 #f;d4 net4 7,post free1 #aas4 home2 #aas4 #f;d4 abroad47 7,see ,evaporating1 ,condensing1 etc41 ,apparatus1 p4 #i47 7,emery47 ,,emery ,,and ,,the ,,emery ,,industry4 ,translated from the ,german of ,a4 ,,haenig4 ,crown #hvo4 #de ,illustrations4 #aaj pp4 ,price #es4 net4 7,post free1 #es4 #c;d4 home2 #es4 #f;d4 abroad47 ,just published4 7,libraries and ,bibliography47 ,,classified ,,guide ,,to ,,technical ,,and ,,commercial ,,books4 ,compiled by ,,edgar ,,greenwood4 ,demy #hvo4 #bbd pp4 #aijd4 ,being a ,subject-list of the ,principal ,british and ,american ,books in ,print2 giving ,title1 ,author1 ,size1 ,date1 ,publisher and ,price4 ,price #es4 net4 7,post free1 #es4 #d;d4 home2 #es4 #f;d4 abroad47 ,,handbook ,,to ,,the ,,technical ,,and ,,art ,,schools ,,and ,,colleges ,,of ,,the ,,united ,,kingdom4 ,containing particulars of nearly #a1jjj ,technical1 ,commercial and ,art ,schools throughout the ,united ,kingdom4 ,with full particulars of the courses of instruction1 names of principals1 secretaries1 etc4 ,demy #hvo4 #aej pp4 ,price #cs4 #f;d4 net4 7,post free1 #cs4 #aj;d4 home2 #ds4 abroad47 ,,the ,,libraries1 ,,museums ,,and ,,art ,,galleries ,,year ,,book1 #aiaj-aa4 ,being the ,third ,edition of ,greenwood's ,british ,library ,year ,book4 ,edited by ,,alex4 ,j4 ,,philip4 ,demy #hvo4 #bhf pp4 ,price #es4 net4 7,post free1 #es4 #d;d4 home2 #es4 #f;d4 abroad47 ,,the ,,plumbing1 ,,heating ,,and ,,lighting ,,annual ,,for #aiaa4 ,the ,trade ,reference ,book for ,plumbers1 ,sanitary1 ,heating and ,lighting ,engineers1 ,builders' ,merchants1 ,contractors and ,architects4 ,quarto4 ,bound in cloth and gilt lettered4 ,price #cs4 net4 7,post free1 #cs4 #d;d4 home2 #cs4 #h;d4 abroad47 ,including the translation of ,hermann ,kechnagel's ,kalender fur ,gesundheits-,techniker1 ,handbook for ,heating1 ,ventilating1 and ,domestic ,engineers1 of which ,scott1 ,greenwood ,son have purchased the sole right for the ,english ,language4 ,,scott1 ,,greenwood ,,son1 ,technical ,book and ,trade ,journal ,publishers1 #h ,,broadway1 ,,ludgate ,,hill1 ,,london1 ,e4,c4 ,telegraphic ,address1 ,printeries1 ,london4 ,tel4 ,no43 ,bank #edjc4 ,january1 #aiab4