,transcriber's notes3 ,italics in the original work are here represented between underscores1 bold face text is represented between equal signs4 ,small capitals from the original work are here represented by ,,all ,,capitals4 ,more ,transcriber's ,notes may be found at the end of this text4 ,detection of the ,common ,food ,adulterants ,,by ,,edwin ,m4 ,,bruce ,,instructor ,,in ,,chemistry1 ,,indiana ,,state ,,normal ,,school ,,london ,,archibald ,,constable ,,co41 ,,ltd4 #aj ,,orange ,,street1 ,,leicester ,,square1 ,w4,c4 #aijg ,copyright1 #aijg ,,by ,d4 ,,van ,,nostrand ,,co4 ,,preface ,because of the recent agitation of the pure food question throughout the country1 health officers1 food-inspectors1 and chemistry teachers and students are constantly called upon to test the purity of various foods4 ,and this usually involves nothing more than making simple qualitative tests for adulterants4 ,in view of the fact that there is now no text or manual devoted exclusively to the qualitative examination of foods1 this little book is offered to those who are interested in this work4 ,its aim is to bring together in one small book the best and simplest qualitative tests for all the common food adulterants4 ,it contains a brief statement of the adulterants likely to be found and the reason for their use4 ,it is hoped that it will be specially valuable to chemistry teachers in furnishing excellent supplementary work in qualitative analysis4 ,but it is hoped that it will find its greatest usefulness in contributing something toward the great pure food reform4 ,it is impossible to make due mention of all the sources from which these various tests have been collected1 but where possible1 the author's name has been associated with the test4 ,,terre ,,haute1 ,,ind4 ,march #be1 #aijg4 ,,table ,,of ,,contents ,,chapter ,i ,,page ,,dairy ,,products #a ,milk--,adulterations of--,coloring matters--,annatto--,caramel-- ,coal-tar colors--,preservatives--,formaldehyde--, boric acid--,salicylic acid--,gelatin--,starch4 ,butter--,adulterations of--,coloring matter--,preparation of sample --,annatto--,coal-tar colors--,saffron--,turmeric--,marigold-- ,process or renovated butter--,oleomargarine--,cottonseed oil4 ,,chapter ,,ii ,,meats ,,and ,,eggs #h ,adulterations of--,fresh and smoked--,preservatives--,potassium nitrate--,boric acid--,sulfurous acid--,salicylic acid--,benzoic acid-- ,canned--,preservatives 7same as those of fresh and smoked meat7-- ,heavy metals--,coloring matter 7see under sausages1 etc47--,fish1 salt1 dried and oysters--,preservatives--,boric acid 7same under smoked and fresh meat7--,coloring matter--,aniline red and cochineal- carmine--,in sausages1 chopped meat1 preparations and corned meat-- ,starch--,in sausages1 deviled meat and similar products--,diseased meats--,horse-flesh in sausages and in mince-meat4 ,eggs--,test for age4 ,,chapter ,,iii ,,cereal ,,products #af ,flour--,adulteration of--,alum--,copper sulfate--,substituted flours --,general test--,corn meal in wheat flour--,wheat flour in rye flour --,ergot in rye flour4 ,bread--,adulterations of--,alum--,copper sulfate4 ,ginger ,cake--,adulterations of--,stannous chlorid4 ,,chapter ,,iv ,,leavening ,,materials #bj ,baking ,powders--,adulterations of--,tartaric acid 7free or combined7--,tartaric acid 7free7--,sulfates 7calcium1 etc47--,gypsum-- ,ammonium salts--,alum4 ,cream of ,tartar--,adulterations of--,tartaric acid 7free or combined7--,aluminium salts--,ammonia--,earthy materials4 ,,chapter ,v ,,canned ,,and ,,bottled ,,vegetables #bd ,adulterations of--,preservatives--,preparation of sample-- ,formaldehyde--,sulfurous acid and the sulfites--,salicylic acid-- ,saccharin--,benzoic acid--,coloring matter--,cochineal--,coal-tar dyes --,copper salts--,in green pickles1 beans1 peas1 etc4--,turmeric--,in mixed pickles--,heavy metals 7other than copper1 same as under meats7--,soaked vegetables--,peas1 beans and corn--,alum--,in pickles-- ,examination of the can or box4 ,,chapter ,,vi ,,fruits ,,and ,,fruit ,,products #cc ,adulterations of--,preservatives--,preparation of sample--,salicylic acid--,benzoic acid--,saccharin--,coloring matter--,coal-tar dyes-- ,cochineal--,acid magenta--,apple juice in jellies made from small fruits--,detection 7see test for starch7--,starch--,in jellies1 jams and such products--,gelatin--,in jellies--,agar agar--,heavy metals-- ,arsenic4 ,,chapter ,,vii ,,flavoring ,,extracts #db ,lemon ,extract--,lemon oil--,citral--,oil of citronella--,tartaric or citric acid--,methyl alcohol--,coloring matter--,turmeric--,coal-tar colors4 ,vanilla ,extract--,adulterations of--,preliminary test--,alkali-- ,foreign resins--,caramel--,tannin--,coumarin4 ,,chapter ,,viii ,,saccharine ,,products #di ,honey--,adulterations of--,general observations--,cane sugar-- ,commercial glucose syrup--,gelatin4 ,maple ,syrup--,adulterations of--,general examination--,glucose4 ,,chapter ,,ix ,,spices #ea ,mustard--,adulterations of--,flour--,coloring matter--,turmeric-- ,martius yellow or analogous coal-tar coloring matter--,cayenne pepper4 ,pepper--,adulterations of--,general test--,ground olive stones-- ,cayenne pepper4 ,,chapter ,x ,,vinegar #ee ,adulterations of--,preparation of sample--,general observations-- ,free mineral acids--,general tests--,sulfuric acid--,hydrochloric acid 7free7--,malic acid--,coloring matter--,caramel--,coal-tar colors--,in wine vinegar--,free tartaric acid--,in wine vinegar4 ,,chapter ,,xi ,,fats ,,and ,,oils #fj ,lard--,adulterations of--,cottonseed oil--,cottonseed stearin--,beef stearin4 ,olive ,oil--,adulterations of--,general test--,cottonseed oil--,peanut oil--,sesame oil--,rape oil4 ,,chapter ,,xii ,,beverages #fe ,coffee--,adulterations of--,general test--,coloring matter-- ,imitation coffee beans--,chicory4 ,tea--,adulterations of--,foreign leaves--,exhausted tea leaves--,lie tea--,facing--,catechu4 ,,pure ,,food ,,tests ,,chapter ,i ,,dairy ,,products ,,milk ,milk is adulterated by watering1 removing the cream or by adding some foreign substance4 ,formaldehyde1 boric acid or salicylic acid may be added to preserve the milk4 ,annatto1 caramel or some coal-tar dye is added1 sometimes to improve the color of the milk1 and at other times to cover up traces of watering4 ,gelatin and starch are added for the same purpose1 though they are not frequently used4 ,,artificial ,,coloring ,,matter ,,annatto ,add acid sodium carbonate to a sample of the milk until it shows a slight alkaline reaction4 ,immerse a piece of filter-paper and leave it in for #ab or #ae hours4 ,if annatto is present1 there will be a reddish-yellow stain on the paper4 ,,caramel ,leach's ,method4--,warm #aej cc4 of the sample and add #e cc4 of acetic acid1 then continue heating it nearly to the boiling point1 stirring while it is being heated4 ,separate the curd by gathering it with the stirring rod or by pouring through a sieve4 ,press out all the whey from the curd and macerate the latter for several hours 7#aj to #ab hours7 in #ej cc4 of ether4 ,it is best to do this in a tightly corked flask1 shaking it frequently4 ,if the milk was uncolored or colored with annatto the curd when thus treated will be white4 ,if the curd is a dull brown color caramel was probably used to color the milk4 ,confirm its presence by shaking a portion of the curd with concentrated hydrochloric acid 7sp4 gr4 #a4bj7 and gently heating4 ,if the acid solution turns blue while the curd does not change its color1 caramel was used to color the milk4 7,remember that the ether-extracted curd must be brown47 ,,coal ,,tar ,,colors ,lythgoe's ,method4--,mix in a porcelain vessel about #ae cc4 each of the sample of milk and hydrochloric acid 7sp4 gr4 #a4bj7 and break up the curd into coarse lumps by shaking gently4 ,if an azo-color was used to color the milk this curd will be pink1 but the curd of normal milk will be white or yellowish4 ,,starch ,the presence of starch in milk may be detected by heating a small quantity of the milk to boiling4 ,when it has cooled add a drop of iodin in potassium iodid1 and if starch is present there will be a blue coloration4 ,,gelatin ,a4 ,w4 ,stokes' ,method4--,dissolve #a part by weight of mercury in #b parts of nitric acid 7sp4 gr4 #a4db74 ,add #bd times this volume of water4 ,mix equal volumes 7about #aj cc47 of this reagent and the milk or cream1 shake well and add #bj cc4 of water4 ,shake again and1 after standing #e minutes1 filter4 ,when a great quantity of gelatin is present the filtrate will be opalescent instead of perfectly clear4 ,to a little of this filtrate in a test tube add the same volume of a saturated aqueous solution of picric acid4 ,if much gelatin is present a yellow precipitate is produced1 smaller amounts produce a cloudiness4 ,if the filtrate is perfectly clear gelatin is absent and picric acid may be added without producing any noticeable effect4 ,,preservatives ,,formaldehyde ,hehner's ,sulfuric ,acid ,test4--,put #aj cc4 of the suspected milk in a wide test tube and pour carefully down the side of the inclined tube about #e cc4 commercial sulfuric acid so that it forms a separate layer at the bottom4 ,a violet coloration at the union of the two liquids indicates the presence of formaldehyde4 ,if the commercial acid is not available1 the pure acid may be used1 but a few drops of ferric chloride must be added4 ,sometimes the charring effect of the acid makes it advisable to use the following test3 ,hydrochloric ,acid ,test4--#b cc4 of #aj per cent ferric chloride is added to one liter of commercial hydrochloric acid sp4 gr4 #a4b 7or any quantity in this proportion74 ,to #aj cc4 of this mixture add #aj cc4 of the milk to be tested4 ,heat the mixture slowly nearly to the boiling point1 in an evaporating dish1 but agitating it all the while to prevent the curd collecting in one mass4 ,if formaldehyde is present1 there will be a violet coloration4 ,it is said that by this test as small a quantity of formaldehyde as #a part in #bej1jjj parts of milk can be detected4 ,it is not so sensitive in sour milk4 ,,boric ,,acid ,turmeric ,paper ,test4--,incinerate some of the milk1 and acidulate the ash with a very few drops of dilute hydrochloric acid and afterwards dissolve it in a few drops of water4 ,place a strip of turmeric paper in this solution for a few minutes1 then remove and dry it4 ,if boric acid either free or combined is present1 the turmeric paper will be turned to a cherry-red color4 ,another way of making this test4--,u4 ,s4 ,dep4 of ,agr41 ,div4 of ,chem41 ,bul4 #fe1 p4 #aaj3 ,make strongly alkaline with lime water1 #be grams of the milk1 and evaporate to dryness on the water bath4 ,destroy the organic matter by igniting the residue4 ,dilute with #ae cc4 of water and acidify with hydrochloric acid4 ,then add #a cc4 of the concentrated acid4 ,dip a piece of delicate turmeric paper in the solution2 and if borax or boric acid is present1 it will have a characteristic red color when dry4 ,ammonia changes it to a dark blue green1 but the acid will restore the color4 7,turmeric paper may be prepared by dipping pieces of smooth1 thin filter paper in a solution of powdered turmeric in alcohol47 ,,salicylic ,,acid 7,this is not often used as a preservative of milk47 ,leach suggests the following method for its detection4--,dissolve one gram of mercury in #b grams of nitric acid 7sp4 gr4 #a4db7 and then add to the solution the same volume of water4 ,add #a cc4 of this reagent to #ej cc4 of the milk to be tested1 and shake and filter4 ,the perfectly clear filtrate is shaken with ether and the ether extract evaporated to dryness4 ,then add a drop of ferric chlorid solution1 and a violet color will be produced if salicylic acid is present4 ,,butter ,butter is often colored with annatto1 saffron1 turmeric1 marigold or coal-tar colors4 ,by a certain process1 stale or old butter is sometimes worked over and made to appear fresh for a time4 ,this is sold under the name of 8process0 or 8renovated0 butter4 ,foreign fats like cottonseed oil1 sesame oil1 or oleomargarine may be substituted for or added to pure butter4 ,,coloring ,,matter ,martin's ,test4--,add #b parts of carbon bisulfid1 a little at a time and with frequent shaking1 to #ae parts of alcohol4 ,shake #be cc4 of this solution with #e grams of the butter1 and let stand for some time4 ,the carbon bisulfid dissolves out the fatty matter and settles to the bottom4 ,the alcohol remains on top and will dissolve out any artificial colors that may be present4 ,if only a little coloring matter is present use more of the butter4 ,,annatto ,evaporate a portion of the extract to dryness and add sulfuric acid to the residue4 ,if annatto is present a greenish-blue color forms4 ,should a pink tint result the presence of a coal-tar color is to be suspected4 ,,coal-,,tar ,,colors ,these colors will dye wool or silk if pieces of the fiber are boiled in the diluted alcoholic extract1 which has first been acidified with hydrochloric acid4 ,the normal butter coloring matter will not dissolve when thus treated4 ,geisler's ,method4--,to a few drops of the clarified fat on a porcelain surface1 add a very little fullers' earth4 ,if a pink to violet-red coloration is produced in a short time the presence of an azo-color is indicated4 ,,saffron ,when saffron is present1 nitric acid colors the alcoholic extract green1 and hydrochloric acid colors it red4 ,,turmeric ,add ammonia to the alcoholic extract1 and if it turns brown it indicates the presence of turmeric4 ,,marigold ,add silver nitrate to the extract1 and if it turns black the presence of marigold is indicated4 ,,process ,,or ,,renovated ,,butter ,heat a little of the suspected butter in a spoon or dish1 and if it is process butter it will sputter1 but not foam much4 ,make the test also with some butter known to be pure and fresh4 ,hess and ,doolittle ,test4--,melt some of the butter 7say #dj grams7 at about #ej ,c4 ,if the butter is pure and fresh the melted fat will clear up almost as soon as it is melted1 while the fat of process butter remains turbid for quite a while4 ,after most of the curd has settled1 decant as much as possible of the fat4 ,pour the remainder on a wet filter4 ,add a few drops of acetic acid to the water that runs through from the filter1 and boil4 ,if it was ordinary butter this filtrate will become milky1 but if process butter a flocculent precipitate will form4 ,,oleomargarine ,immerse a test tube1 containing some of the filtered fat1 in boiling water for #b minutes4 ,make a mixture of #a part glacial acetic acid1 #f parts ether1 and #d parts alcohol4 ,add to #bj cc4 of this mixture in a #ej cc4 test tube1 #a cc4 of the heated fat which may be transferred by means of a hot pipette4 ,stopper the tube and shake it well4 ,immerse in water at #ae or #af ,c4 ,pure butter when thus treated remains clear for quite a while4 ,there will be only a very little deposit after standing an hour1 but oleomargarine gives a deposit almost immediately1 and in a few minutes there will be a copious precipitate4 ,when the oleomargarine in butter is in about the proportion of #a 3 #aj1 it will not separate much short of #ae minutes4 ,,cottonseed ,,oil ,the presence of this oil may be detected by ,halpen's test1 which is given under lard1 page #fj4 ,,chapter ,,ii ,,meats ,,and ,,eggs ,meats are preserved by treating them with potassium nitrate1 boric acid1 sulfurous acid1 salicylic acid1 or benzoic acid4 ,cheap meat may be substituted for the more expensive4 ,a few cases of horse meat in mince meat and sausages have been discovered4 ,diseased and stale meats have been found on the market4 ,canned meats often contain zinc1 tin1 and lead1 and sometimes even arsenic4 ,aniline-red or cochineal-carmine may be added to improve the color of chopped or ground meats4 ,starch is sometimes added to sausage and similar meat4 ,fish and oysters may be preserved with boric acid or borax4 ,,fresh ,,and ,,smoked ,,products--,,preservatives ,,potassium ,,nitrate 7,,saltpeter7 ,corned and smoked meats are usually preserved with saltpeter4 ,since smoked and cured meats are used in making potted meats1 saltpeter is quite frequently found in the latter4 ,it may be detected by the usual test for nitrates since no other nitrate is apt to be present1 though one may identify the metal by the qualitative test for potassium4 ,to test for nitrates treat a little of the meat with #b or #c cc4 of a #a per cent solution of diphenylamine in strong sulfuric acid4 ,if a nitrate is present a deep blue color forms instantly1 which is not obscured by the charring effect of the acid4 ,,boric ,,acid ,pick apart into fine pieces about #be or #ej grams of the lean meat and warm with a little water which has a few drops of hydrochloric acid in it4 ,soak a piece of turmeric paper in the extract1 and if boric acid is present the paper will be colored rose-red when it is dry4 ,a weak alkali turns this colored paper olive4 ,another method is to burn a piece of the meat to an ash1 after being treated with lime water4 ,make a solution of the ash and make slightly acid with hydrochloric acid4 ,then test with the turmeric paper with the same results as in the above method4 ,,sulfurous ,,acid ,u4 ,s4 ,dep4 ,agr41 ,bureau ,chem41 ,bul4 #ac1 ,part #aj3 ,digest #dj or #ej grams of the meat in hot water1 treat with #aj cc4 glacial phosphoric acid to coagulate the proteids4 ,strain through a cotton bag and transfer the filtrate to a short-necked flask and distil receiving the first part of the distillate in a solution of iodin4 ,boil1 and add barium chloride4 ,if sulfurous acid is present1 it will be oxidized to sulfuric acid and precipitated as barium sulfate by the barium chlorid4 ,more than a mere trace of the precipitate proves that some sulfite was used to preserve the meat4 ,another method suggested by ,kmmerer is to place the meat on paper1 which has been saturated with potassium iodate moistened with dilute sulfuric acid 7#a 3 #h72 nitric oxid must not be present4 ,if sulfurous acid is present a deep blue color forms at once4 ,a trace of this color may form after some time with meat that is not fresh1 hence this method cannot be used in examining canned meat4 ,,salicylic ,,acid ,heat #ej grams of the meat in #ej cc4 of water4 ,add #aj cc4 of a strong solution of glacial phosphoric acid and strain through a cotton bag4 ,extract the filtrate with a little ether 7about #ej cc47 in a separatory funnel4 ,let the ether evaporate spontaneously4 ,take up the residue with #c cc4 of water1 and add one or two drops of a one-half per cent solution of ferric chlorid4 ,if salicylic acid is present the mixture will be purple or violet4 ,leach makes the same test by slightly acidifying a portion of the lean meat1 then extracting with ether1 and evaporating to dryness and testing the residue with a drop of ferric chlorid solution4 ,a deep violet coloration is produced if salicylic acid is present4 ,,benzoic ,,acid ,mohler's ,method4--,prepare a sample as in the test for salicylic acid by heating #ej grams of the meat in #ej cc4 of water4 ,add #aj cc4 of a concentrated solution of glacial phosphoric acid1 and strain through a cotton bag4 ,neutralize with sodium hydrate and evaporate to dryness or to a small volume4 ,after treating with #c cc4 of concentrated sulfuric acid1 heat till white fumes appear4 ,add #d or #e crystals of potassium nitrate and continue heating until the solution is colorless or nearly so4 ,when cool dilute with water1 add an excess of ammonia1 and place in a narrow vessel like a test tube4 ,add one or two drops of ammonium sulfid carefully so that the liquids do not mix4 ,if the surface of the liquid immediately becomes red1 benzoic acid is present4 ,if this test is not carefully performed1 it is worthless1 as other substances give similar results4 ,confirm its presence by neutralizing the aqueous solution of the extracted benzoic acid with sodium hydroxid2 concentrate to a very small volume4 ,acidify with sulfuric acid4 ,a white flocculent precipitate shows the presence of considerable benzoic acid4 ,,canned ,,meat ,if in preparing canned meat only fresh meat is used1 there is little need for the use of preservatives1 but as considerable smoked and cured meat is thus used1 preservatives may find their way into canned meat4 ,the same preservatives should be looked for as in fresh and smoked meat and the same test made for each4 ,,heavy ,,metals ,a4 ,h4 ,allen's ,method4--,about #be grams of the substance is mixed slowly with enough strong1 pure sulfuric acid to just moisten the mass1 avoiding an excess4 ,heat on a water-bath for a short time1 then raise the temperature gradually1 and maintain till the chlorids seem to be decomposed4 ,it must not be hot enough1 however1 to volatilize the sulfuric acid4 ,then add #a cc4 of strong nitric acid and heat till red fumes are given off4 ,freshly ignited magnesia in the proportion of #j4e gram for each cc4 of sulfuric and nitric acid previously used is now stirred into the mass and the whole ignited at a dull red heat4 ,this is best done in a gas-muffle4 ,when cool1 moisten the ash with nitric acid and gently re-ignite1 repeating this treatment till the carbon is entirely consumed4 ,treat the residue with #h or #aj drops of strong sulfuric acid1 heat till fumes are given off1 cool1 boil with water1 dilute to about #ajj cc4 and saturate with hydrogen sulfid1 filter1 examine as follows3 ,zinc and iron may be in ,lead1 tin1 copper1 and calcium1 if present1 solution4 ,add bromine will be in the precipitate and residue4 water to destroy hydrogen ,fuse the mass in a porcelain crucible for sulfid and to oxidize the at least ten minutes with #b grams each of iron1 boil and add ammo- potassium and sodium carbonates and half nium hydrate in excess1 as much sulfur4 ,after cooling1 boil with boil again and filter4 water and filter4 ---------------------------------------- --------------------------- ,the precipitate,filtrate1 ,residue4 ,add hydrochloric ,the filtrate may will contain when blue1acid and boil as long as contain tin4 the iron and proves thehydrogen sulfid is given ,acidify with the phosphates4presence off4 ,a few drops of bro- acetic acid1 and of nickel4mine water will complete if tin is pres- the oxidation of the ent a yellow copper sulfid4 ,filter1 andprecipitate of add ammonium hydroxid in stannic sulfid excess to the filtrate4 will form4 ,when the filtrate is blue1 it indicates the presence of copper4 ,acidify the filtrate with acetic acid and test for lead by adding potassium chromate1 a yellow precipitate being formed when it is present4 ---------------------------------------- --------------------------- ,i4 ,heat to boiling and add potassium ferrocya- nid4 ,a white pre- cipitate or turbi- dity in- dicates zinc4 ,,fish ,,salt ,,dried ,,and ,,oysters ,this kind of meat is often preserved with boric acid and borax4 ,they may be detected by the method given under fresh and smoked meat4 ,,coloring ,,matter ,sausages and other chopped meat preparations1 together with corned meat that has been cured without saltpeter1 are often treated with artificial coloring matter4 ,aniline red and cochineal carmine are usually employed for this purpose4 ,the former may be detected1 according to ,allen1 by picking the meat apart and treating it with methylated spirit1 strain or filter the extract and take up with water4 ,then a piece of white wool 7nun's veiling will do7 is immersed in the boiling liquid and1 if it is dyed red1 rosaniline is present4 ,cochineal-carmine may be detected by the method used by ,klinger and ,bujard4 ,cut up fine about #bj grams of the meat and heat in a water-bath with water and glycerine mixed in equal parts4 ,if the above coloring matter is present the liquid will become quite red in color1 if not present a slight yellow color results from this treatment4 ,if a spectroscope is available this dye is easily recognized4 ,,starch ,,in ,,sausage1 ,,deviled ,,meat1 ,,and ,,similar ,,products ,cracker and bread crumbs are often added to these preparations and their presence is best detected by examining the amount of starch present4 ,do this by boiling some of the sample in water1 and when cool adding a drop or two of iodin reagent4 ,the usual blue color is produced if much starch is present4 ,if there is only a little starch1 it may be necessary to examine it under the microscope to determine whether the starch is from the pepper and other spices used or from some cereal4 ,,diseased ,,meat ,the following method is recommended by ,ebers4--,hold a small piece of the suspected meat over a mixture of #a cc4 hydrochloric acid1 #c cc4 alcohol1 and #a cc4 of ether4 ,the formation of ammonium chlorid fumes shows that decomposition has begun4 ,do not mistake the fumes of the acid for those of ammonium chlorid4 ,,horse ,,flesh ,,in ,,sausage ,,and ,,mince ,,meat ,this sophistication is not common in this country4 ,horse flesh is detected by testing for glycogen1 which is present in it in larger quantities than in other meats4 ,courley ,coremon's ,test4--,boil #ej grams of the meat for a half hour with water1 strain1 and to a portion of the filtrate add a few drops of potassium iodid-iodin solution 7potassium iodid #j4d gram2 iodin #j4a gram2 water #bj cc474 ,if considerable horse meat is present the glycogen will color the liquid dark brown1 which disappears on heating1 but returns on cooling4 ,,eggs ,it sometimes happens that one wishes to know the age of eggs without opening them4 ,delarne's ,test4--,place the egg in a #aj per cent solution of common salt4 ,perfectly fresh eggs sink to the bottom4 ,those remaining immersed1 but suspended in the liquid1 are at least three days old1 while those rising to the surface and floating are more than five days old4 ,the older the egg1 the higher it floats and the more it will stand on end4 ,this test is not applicable to eggs that have been preserved4 ,hold the egg between a bright light and the eye1 and if the air chamber is small1 and no dark spots but instead a rather uniform rose-colored tint is seen1 the egg is fresh4 ,if the contents appear cloudy and the air chamber larger1 the egg is not fresh4 ,the darker the contents of the egg the older it is4 ,,chapter ,,iii ,,cereal ,,products ,,flour ,sometimes a cheaper or inferior grade of flour is substituted for one of higher quality1 and even a different kind of flour may be substituted1 as corn meal in wheat flour1 or wheat in rye flour4 ,alum may be added by millers to cover up traces of bad flour1 and by bakers to make the bread white when a bad or cheap flour is being used4 ,copper sulfate also may be added to improve the appearance4 ,occasionally rye flour is made from rye upon which ergot has developed4 ,stannous chlorid and potassium carbonate are added to ginger cake to give the same color to the product made of molasses and a poor grade of flour as that made from good flour and honey4 ,,alum ,wynther ,blyth ,method4--,add a little water to the sample and macerate4 ,soak pieces of gelatin in the solution and leave for a half day1 remove the gelatin and dip the pieces in a mixture of equal volumes of a fresh tincture of logwood and a saturated solution of ammonium carbonate4 ,the gelatin strips will turn blue if alum is present4 ,bell ,carter ,method4--,make a fresh #e per cent tincture of logwood in methyl alcohol4 ,dampen about #aj grams of the flour with water and add #a cc4 of the logwood tincture and the same quantity of a saturated solution of ammonium carbonate4 ,pure flour gives a pinkish color which fades to buff or brown4 ,the presence of alum produces a lavender or bluish tint which becomes more distinct as it dries4 ,,copper ,,sulfate ,this adulterant may be detected in either flour or bread1 by soaking the flour or bread in a dilute solution of potassium ferrocyanid acidulated with acetic acid4 ,if copper be present a purplish or reddish-brown coloration will be produced4 ,,substituted ,,flours ,vogel's ,method4--,make a mixture of alcohol 7#gj per cent71 #ie parts1 hydrochloric acid #e parts4 ,treat a sample of the flour in a test tube with this reagent4 ,shake well4 ,heat to boiling and allow to settle4 ,a colorless fluid shows the flour to be pure1 a straw-colored tint indicates the presence of gruffs with bran1 an orange-yellow proves the presence of corn-cockle flour1 a flesh-colored liquid indicates the presence of ergot1 while a green color indicates buckwheat flour4 ,,corn ,,meal ,,in ,,wheat ,,flour ,kraemer claims to be able to detect as small amount as #e per cent of maize in wheat flour1 by the following test4--,mix a gram of the flour with #ae cc4 of good glycerin1 and heat to boiling for a short time4 ,if corn meal is present1 there will be an odor like that of pop corn4 ,,wheat ,,in ,,rye ,,flour ,kleeburg recommends the following test4--,a little of the flour is mixed on a piece of common window glass or microscope slide1 with sufficient water 7at #de ,c47 to float the flour particles4 ,spread the mixture out over the glass1 and press another glass down upon it4 ,when wheat flour is present1 white spots will be seen1 and if the glasses are slid upon each other the spots will pull out into threads1 and the thicker and longer they are the more wheat flour there is present4 ,,ergot ,,in ,,rye ,,flour ,boettger gives the following chemical test for ergot4--,heat #aj to #ae minutes with an equal quantity of ether1 adding a few crystals of oxalic acid4 ,when ergot is present a reddish color develops4 ,another ,method4--,bul4 #ea1 ,bureau of ,chem4 ,digest #bj grams of the suspected flour1 with boiling alcohol1 till no more color is extracted4 ,add #a cc4 of sulfuric acid 7#a 3 #c71 and if ergot is present the solution will be colored red4 ,,bread ,,alum ,moisten a piece of the bread with water1 and then with a logwood solution 7#e grams logwood digested in #ajj cc4 of alcohol74 ,if alum is present the bread will become lavender blue in two or three hours4 ,pure bread would have a red-brown tint4 ,to prove the presence of alum1 the blue color must be permanent at the temperature of boiling water4 7,the logwood used in this test must be pure47 ,blyth's ,test4--,macerate #aej grams of the sample for #de or #ej hours in a couple liters of water2 after straining through muslin1 evaporate to a small volume over a low flame4 ,immerse a strip of gelatin in this liquid1 and then in a logwood solution 7same as in last test71 and if alum is present it will acquire the lavender color4 ,if the bread in either of these tests is sour1 the following modification 7,vanderplanken7 must be made4 ,reduce #ae grams of the sample to a paste with water and some pure chlorid of sodium1 adding #aj drops of a fresh alcoholic solution of logwood1 after which add #e grams of pure potassium carbonate4 ,mix well1 and after washing with #ajj cc4 of water into a vessel allow to settle4 ,if alum is present the liquid will soon become reddish-violet1 and if not present it will be blue4 ,,copper ,,sulfate ,,see ,,test ,,for ,,copper ,,sulfate ,,in ,,flour ,,ginger ,,cake ,tin may be detected by the method for heavy metals under meat4 ,,chapter ,,iv ,,leavening ,,materials ,,baking ,,powders ,baking powders consist of bicarbonate of soda and an acidifying agent as acid potassium tartrate1 acid calcium phosphate1 tartaric acid or alum4 ,some powders contain both acid calcium phosphate and alum4 ,the kind of powder is determined by testing for these4 ,gypsum has been added to baking powders to increase the weight4 ,,tartaric ,,acid ,,free ,,or ,,combined ,wolff's ,method4--,if no starch is present1 mix a little of the powder with some dry resorcin4 ,add a few drops of sulfuric acid and heat gently4 ,a rose-red color forms if tartaric acid or tartrates are present4 ,the color should disappear when diluted with water4 ,when starch is present1 mix well by shaking about #e grams of the powder with #bej cc4 of cold water4 ,let the insoluble matter settle and pour the liquid upon a filter4 ,evaporate the filtrate to dryness1 treat the powdered residue with a few drops of a #a per cent solution of resorcin4 ,add #c cc4 of strong sulfuric acid1 heat slowly4 ,a rose-red color forms if tartaric acid is present4 ,the color should be destroyed on the addition of water4 ,this test is applicable in the presence of phosphates and the acid may be free or combined4 ,,tartaric ,,acid ,,free ,make an absolute alcoholic extract of #e grams of the powder and evaporate the alcohol4 ,add sufficient dilute ammonia to dissolve the residue1 place in a test tube and drop in a crystal or two of silver nitrate4 ,heat gently1 and a silver mirror will form if tartaric acid is present4 ,,sulfates ,,calcium1 ,,etc4 ,boil a portion of the sample gently with strong hydrochloric acid1 add barium chlorid4 ,a white precipitate of barium sulfate will form if sulfuric acid is present4 ,,gypsum ,,calcium ,,sulfate ,ash a portion of the sample and make the usual qualitative tests for calcium sulfate4 ,,ammonium ,,salts ,extract a few grams of the sample with cold water1 boil the extract with sodium hydroxid and place a piece of moist red litmus paper in the steam4 ,it will be colored blue if ammonia is present4 ,,alum ,reduce to an ash about #b grams of the powder in a platinum dish4 ,extract with boiling water1 add ammonium chlorid solution to the filtrate until a distinct odor of ammonia is given off4 ,if a flocculent precipitate forms it indicates the presence of alum4 ,this test for alum is applicable in the presence of phosphates4 ,mrs4 ,richards4--,cover some logwood chips 7they must be pure7 with water and bring to a boil4 ,repeat this four times1 saving only the last decoction4 ,shake some of the sample 7a couple of teaspoonfuls7 in a beaker half full of water4 ,when it ceases effervescing1 strongly acidify with acetic acid4 ,add a few drops of the logwood extract1 and if alum is present a bluish-red color will appear4 ,,cream ,,of ,,tartar ,cream of tartar is bitartrate of potassium and is obtained from the lees deposited in wine casks4 ,if gypsum has been used to clarify the wine1 it will be present in the cream of tartar as calcium tartrate4 ,other adulterants of cream of tartar are acid calcium phosphate1 starch1 gypsum1 and alum4 ,,tartaric ,,acid ,,free ,,or ,,combined ,if the sample is known to be free from starch the following test may be made3 ,mix a bit of the powder with a small quantity of dry resorcin and add a few drops of concentrated sulfuric acid4 ,heat slowly1 and if a rose-red color forms1 which disappears when diluted with water1 there is present either tartaric acid or a tartrate4 ,when the sample contains starch1 shake about #d or #e grams of it a number of times with #bej cc4 of cold water in a large flask4 ,pour on a filter after the insoluble material has settled and evaporate the filtrate to dryness4 ,the residue is to be tested for tartaric acid and tartrates1 the same as when starch was absent4 ,,aluminium ,,salts ,mix equal quantities 7about #a gram7 of the sample and sodium carbonate and burn to an ash4 ,extract with boiling water and filter4 ,add to this filtrate enough ammonium chlorid solution to cause a distinct evolution of ammonia4 ,the formation of a flocculent precipitate shows the presence of aluminium4 ,this test may be used when phosphates are present4 ,,ammonia ,,present ,,in ,,the ,,form ,,of ,,ammonia ,,alum ,,or ,,ammonium ,,carbonate ,make a cold water extract of the powder and boil it with sodium hydroxid4 ,test the steam with moist red litmus paper4 ,,earthy ,,materials ,treat the sample with warm potassium hydroxid4 ,a residue indicates some earthy material4 ,,chapter ,v ,,canned ,,and ,,bottled ,,vegetables ,no class of foods on the market has less need for antiseptics than canned goods1 yet their use is rather common4 ,products thus treated are easier canned and are not so apt to spoil4 ,the chemicals used as preservatives are sulfurous acid1 and the sulfites1 salicylic acid and saccharin1 benzoic acid1 and sometimes formaldehyde4 ,sulfurous acid is used to bleach such foods as canned corn4 ,saccharin possesses some antiseptic properties1 but its main use is as a sweetener4 ,alum is used to make pickles hard and crisp4 ,some canned or bottled goods1 as tomato-catsup1 is colored with cochineal or coal-tar dyes4 ,green pickles1 beans1 peas1 and such vegetables are colored by copper salts or are cooked in copper vessels1 with the addition of acetic acid1 hence the beautiful green color4 ,turmeric is sometimes used to color mixed pickles4 ,the heavy metals as lead1 zinc1 and tin are generally present in canned goods1 the amount varying with the corrosive power of the vegetable4 ,when there is a year of scarcity in corn1 peas1 beans1 and such vegetables1 the dried product is often soaked and canned4 ,some of this goods is sold for the regular green vegetable1 while some may be properly marked 8,soaked ,goods40 ,,preservatives ,it is best to make a systematic examination for the different preservatives4 ,the sample may be prepared by mixing #ej grams of the pulped material with sufficient water in a #bej cc4 graduated flask4 ,add phosphoric acid till distinctly acid in reaction4 ,fill to the mark with water4 ,place in a distilling flask1 and distil in a linseed oil or a paraffin bath till #cj cc4 have been collected4 ,save this distillate for the following tests4 ,,formaldehyde ,to #e cc4 of the above distillate in a test tube1 add #b or #c drops of a #a per cent aqueous solution of phenol and mix well4 ,incline the tube and carefully pour down the side #e cc4 of concentrated commercial sulfuric acid so that the two liquids do not mix4 ,if formaldehyde is present there will be a crimson zone at the plane of union of the solutions4 ,this coloration takes place when the formaldehyde is present in the proportion of #a part in #ajj1jjj parts4 ,when there is a greater quantity of formaldehyde present a white turbidity or a light-colored precipitate forms above the coloring4 ,phenylhydrazine ,hydrochloric ,test4--,dissolve #b grams of phenylhydrazine hydrochlorid and #c grams of sodium acetate in #bj cc4 of water4 ,add #b to #d drops of this reagent and the same number of drops of sulfuric acid to #a or #b cc4 of the above distillate1 to be examined in a test tube4 ,a green coloration is produced when formaldehyde is present4 ,hydrochloric ,acid ,test4--,add #e cc4 of the distillate to be tested to about #e cc4 of milk known to be pure1 and about #aj cc4 of concentrated hydrochloric acid 7sp4 gr4 #a4b7 which contains #a cc4 of a #aj per cent ferric chlorid solution to each #ejj cc4 of the acid4 ,heat slowly to #hj or #ij ,c4 over the free flame1 agitating it at the same time to break up the curd4 ,a violet coloration indicates formaldehyde4 ,,sulfurous ,,acid ,,and ,,the ,,sulfites ,free sulfurous acid is not largely used as a food preservative1 though its salts are quite commonly employed4 ,detection4--,mix #aej grams of the finely ground sample with enough water to make a thin paste4 ,acidify with phosphoric acid and distil till #be cc4 have been collected4 7,the delivery tube of the condenser should dip below the surface of a little water47 ,treat the distillate with a few drops of bromine water and boil for a short time4 ,if a precipitate forms on the addition of barium chlorid the presence of sulfurous acid is indicated4 ,,salicylic ,,acid ,acidify #ej cc4 of the sample with sulfuric acid1 and shake vigorously with #ej cc4 of a mixture of equal parts of ether and petroleum spirit4 ,when the liquids have separated1 draw off as much as possible of the solvent and filter4 ,if an emulsion forms use a centrifugal machine1 and evaporate with a small flame4 ,if needle-shaped crystals form1 salicylic acid is present4 ,add a few drops of water and a drop of very dilute ferric chlorid solution in such a way that the solutions will come together slowly4 ,the presence of salicylic acid gives a purple or violet color4 ,,saccharin ,this is used quite extensively as a sweetening agent in canned sweet corn1 and other similar products4 ,macerate about #bj grams of the sample after mixing with #cj to #dj cc4 of water and strain through muslin4 ,acidify with #a or #b cc4 of sulfuric acid 7#a to #c7 and extract with ether4 7,if an emulsion forms1 use a centrifugal machine47 ,separate the ether layer and let the ether evaporate spontaneously and use the residue in the following tests3 ,take up a part of the residue with water and taste4 ,if it is very sweet saccharin is present4 ,confirm by the following3 ,schmidt's ,test4--,add about #a gram of sodium hydroxide to another part of the residue1 and heat in an air-oven or oil bath1 for half an hour at about #bej ,c41 to convert the saccharin into salicylic acid4 ,after it has cooled1 acidify with sulfuric acid1 extract and test for salicylic acid with #b or #c drops of ferric chlorid solution1 letting the solutions come together slowly4 ,a purple or violet coloration proves the presence of salicylic acid1 which in turn indicates the presence of saccharin4 ,this test cannot be used if salicylic acid was used as a preservative in the original product4 ,a test for the acid should first be made4 ,bornstein's ,test4--,heat the remainder of the above ether residue with resorcin and a very little sulfuric acid till it begins to swell4 7,it is best to do this heating in a test-tube47 ,let cool till the action stops1 heat again and repeat the operation several times4 ,after cooling the last time1 dilute with water and add sodium hydrate till neutral4 ,if saccharin is present1 there will be a red-green fluorescence4 ,,benzoic ,,acid ,acidify #ej cc4 of the sample with sulfuric acid and shake vigorously with #ej cc4 of a mixture of equal parts of ether and petroleum spirit4 ,let the liquids separate1 then draw off as much as possible of the solvent and filter4 7,use a centrifugal machine if an emulsion forms47 ,separate the extract into #b parts and evaporate each to dryness over a small flame and make the following tests3 ,ferric ,chlorid ,test4--,dissolve one of these residues in ammonia1 and evaporate to dryness on a water-bath4 ,take up the residue with warm water1 filter1 and collect the filtrate in a small test tube4 ,add a drop of ferric chlorid solution1 and if benzoic acid is present a characteristic flesh or brownish colored precipitate of ferric benzoate forms4 ,sometimes in such products as sweet pickles1 a basic ferric acetate precipitate comes down and the following test had better be applied4 ,peter's ,method4--,take about #j4a gram of the second part of the above ether residue1 place in a large test tube 7about #ej cc47 and dissolve in #e to #h cc4 of concentrated sulfuric acid4 ,add from #j4e to #j4h gram of barium peroxide1 a little at a time4 ,shake each time and cool in water if necessary4 ,this should produce a permanent froth on the sulfuric acid4 ,let stand #be or #cj minutes1 then fill the tube three fourths full of water1 shake and cool rapidly to the temperature of the room1 and filter off the barium sulfate4 ,extract with chloroform or ether4 ,remove the extract and test it for salicylic acid with dilute ferric chlorid4 7,see first test under salicylic acid47 ,in this method salicylic acid must first be proven absent4 ,mohler's ,test4--,treat the remainder of the second part of the above ether residue with #b or #c cc4 of concentrated sulfuric acid4 ,heat till white fumes appear4 ,add a few crystals of potassium nitrate and when cool dilute with water4 ,add an excess of ammonia1 then a drop or two of ammonium sulfid4 ,if a red color appears immediately on the surface1 it shows the presence of benzoic acid4 ,,coloring ,,matter ,,in ,,catsups ,,and ,,tomatoes ,,cochineal ,girard and ,dupre ,test4--,shake well a portion of the sample with water and filter1 acidify with hydrochloric acid1 then extract with amyl alcohol1 and if cochineal is present the extract will be colored yellow or orange1 the particular shade depending on the amount of cochineal present4 ,remove the amyl alcohol and wash with water until it is neutral4 ,to half of this1 add a very dilute solution of uranium acetate1 drop by drop1 and shaking well after the addition of each drop4 ,cochineal1 if present1 will produce a characteristic emerald-green color4 ,confirm by adding a drop or two of ammonia to the second half of the amyl alcohol extract and a violet coloration will be produced if cochineal is present4 ,,coal-,,tar ,,coloring ,,matter ,sostegni and ,carpentieri ,test4--,free from grease a piece of woolen cloth 7nun's veiling will do7 by boiling first in very dilute caustic soda solution and then in water4 ,acidify a portion of the sample with #b to #d cc4 of #aj per cent solution of hydrochloric acid and filter4 ,strips of the cleansed cloth are boiled in this filtrate for #e or #aj minutes1 then removed1 washed in water and boiled with very dilute hydrochloric acid solution4 ,wash out the acid and dissolve the color from the cloth by boiling in a solution of ammonium hydroxid 7#a to #ej74 7,the time required will depend upon the dye present47 ,remove the cloth from the solution and acidify the latter with hydrochloric acid and another piece of the cleansed cloth is immersed and again boiled4 ,this second dyeing fixes only coal-tar colors on the cloth1 hence1 no fear of mistaking them for the natural color of the vegetable4 ,,in ,,green ,,pickles1 ,,beans1 ,,peas1 ,,etc4 ,,copper ,,salts ,burn #bj grams of the sample to an ash and wet the ash with concentrated nitric acid1 dilute with water and boil4 ,add ammonia till strongly alkaline and filter4 ,if the filtrate is blue1 copper is present4 ,confirm by acidifying the filtrate with acetic acid and adding potassium ferrocyanid4 ,a red or brownish precipitate or coloration proves the presence of copper4 ,the test for other heavy metals may be made by the general method given under meats4 ,,in ,,mixed ,,pickles ,,turmeric ,shake with alcohol to extract the color4 ,soak a piece of filter paper in the extract and dry in an air oven at #ajj ,c4 ,wet the filter paper with a weak solution of boric acid to which a very little hydrochloric acid has been added4 ,if turmeric is present1 a cherry-red color will appear when the filter paper is dry4 8,,soaked0 ,,vegetables ,,peas1 ,,beans1 ,,and ,,corn ,there is really no chemical test for this class of foods4 ,certain helpful directions given in ,bul4 #fe1 p4 #ed1 of the ,bureau of ,chem41 will assist in identifying such goods4 ,all or nearly all of the green color of peas and beans is destroyed by the process of 8soaking40 ,they have the appearance of the well-matured product1 and are firm and mealy with well-formed cotyledons4 ,the process of soaking starts the growth of the caulicle of the pea4 ,the kernel of corn is plump and hard and does not have the milky consistency of the immatured product4 ,the characteristic succulence of the green pea1 bean1 and corn is absent in the soaked product4 ,,alum ,,in ,,pickles ,this is sometimes added to the pickling solution to produce hardness and crispness4 ,burn to ash a sample of the pickles1 and1 if they are free from copper1 fuse in a platinum dish with sodium carbonate4 ,extract with boiling water1 and after filtering add ammonium chlorid solution4 ,if alum is present1 a flocculent precipitate will form4 ,,examination ,,of ,,the ,,can ,,or ,,box ,,in ,,which ,,vegetables ,,are ,,sealed ,generally when the ends of a can are convex1 instead of plane or concave1 it is spoiled4 ,in the souring of canned sweet corn1 it is exceptional that the ends are forced outward4 ,strike the can and the spoiled cans will give a dull sound while the good ones will give a distinct tone4 ,some practice will be necessary to use this test4 ,one can judge of the amount of tin dissolved by the corrosion of the inside of the can4 ,reject cans that show much rust around the cap on the inside of the head4 ,if more than one hole is found soldered in the cap1 reject the can4 ,cans of salmon are the only exception that has come to the author's notice4 ,a second hole1 in general1 indicates that decomposition had set in and the can had been punctured and resealed4 ,,chapter ,,vi ,,fruits ,,and ,,fruit ,,products ,salicylic acid1 benzoic acid1 and saccharin are used to preserve fruits4 ,the last is also added as a sweetener instead of sugar4 ,many fruit products lose their color with age1 and to give them a lasting color they are treated with a coal-tar dye1 cochineal1 acid magenta1 or caramel4 ,a very small per cent of the jams and jellies sold are strictly pure4 ,these cheap products are made up principally of apple juice and commercial glucose2 artificial essences are added to imitate the real flavor4 ,in cheap jellies made of apple juice and glucose syrup1 a 8coagulator0 is used2 usually sulfuric acid and alum1 also citric and tartaric acids may be used for this purpose4 ,starch1 gelatin1 and agar are used as gelatinizing agents4 ,fruits put up in tin cans may dissolve the heavy metals as tin1 zinc1 lead1 and even arsenic4 ,,preservatives ,preparation of the ,sample4--,dissolve #be or #cj grams of the sample in water which has been acidified with sulfuric acid 7#a to #c71 then extract with ether1 and remove the ether layer and let it evaporate spontaneously4 ,the residue may contain salicylic acid1 benzoic acid1 or saccharin4 ,take up with a little water and make the following tests3 ,,salicylic ,,acid ,place a few drops of this extract in a test tube and add a drop or two of a #j4e per cent solution of ferric chlorid4 ,if salicylic acid is present1 there will be a purple coloration4 ,,benzoic ,,acid ,mohler's ,test4--,add #b to #c cc4 of strong sulfuric acid to a second portion of the above ether extract and heat until white fumes appear4 ,then add a few crystals of potassium nitrate and heat again4 ,continue adding the nitrate and heating till the solution is colorless or only a very light yellow4 ,dilute with about #e cc4 of water when cool1 neutralize with ammonia4 ,it should be filtered when not clear or when crystals of ammonium or potassium sulfate are formed4 ,add a few drops of ammonium sulfid to the filtrate in such a way as to prevent the mixing of the liquids4 ,the sulfid will be on top4 ,if a bright cherry-red color forms where the two liquids meet1 either benzoic acid or saccharin is present4 ,distil and the benzoic acid will pass over1 extract the distillate in the usual way and apply the above test to it for benzoic acid4 ,,saccharin ,taste a third portion of the ether extract4 ,a very sweet taste indicates saccharin4 ,a further test can be made by adding #a or #b grams of sodium hydroxid to the rest of the ether extract and heating a half hour in an oil bath at #bej ,c4 ,dissolve in water when cool1 acidify with dilute sulfuric acid and extract with ether4 ,the saccharin will have been converted into salicylic acid1 which may be identified by the usual test for that acid4 ,this test presupposes the absence of salicylic acid in the original material4 ,,coloring ,,matter ,,coal-,,tar ,,dyes ,to attempt to identify the particular dye used in every case would be quite beyond the object of this set of simple tests4 ,a general test showing the presence of a coal-tar dye is probably all that is usually desired4 ,sostegni and ,carpentieri ,test4--,such a test may be made by dissolving #ae grams of the fruit product in #ajj cc4 of water1 filtering and acidifying with a small quantity of a #aj per cent solution of hydrochloric acid and again filtering4 ,place in the filtrate strips of white woolen cloth 7nun's veiling will do7 which have been freed from grease by boiling first in very dilute caustic soda solution1 then in water1 and boil for #e to #aj minutes4 ,remove the cloth and wash it in water1 then boil in very dilute hydrochloric acid4 ,stir the cloth in water to remove the acid and dissolve the color by boiling in a solution of ammonium hydroxid 7#a to #ej74 ,the time required will depend upon the particular dye used4 ,remove the cloth from the solution and acidify the latter with hydrochloric acid1 a slight excess is better1 and another piece of the cleansed cloth is immersed and again boiled4 ,nothing but coal-tar dyes will color in this second dyeing4 ,,cochineal ,girard and ,dupre ,test4--,see tests for cochineal under 8,catsups and tomatoes40 ,,acid ,,magenta ,girard and ,dupre4--,make about #ajj cc4 solution of the fruit1 filter1 and neutralize with potassium hydroxid 7strength #e to #ajj72 about #b cc4 will be needed4 ,add #d cc4 of mercuric acetate solution 7#a to #aj71 shake and filter4 ,by this treatment the filtrate should be colorless and slightly alkaline4 ,add sulfuric acid till there is a slight excess4 ,a colorless solution indicates the absence of acid magenta1 while a light violet-red shows its presence1 providing the amyl-alcohol extract showed no other dye to be present4 ,,caramel ,amthor's ,test4--#aj cc4 of a solution of the fruit is put into a deep1 narrow glass 7a bottle may be used74 ,add #cj to #ej cc4 of paraldehyde1 to be gaged by the intensity of the coloring4 ,then add a sufficient quantity of absolute alcohol to make the solutions mix4 ,if caramel is present1 a brownish-yellow to dark-brown precipitate will be formed1 decant1 wash the precipitate once with absolute alcohol1 dissolve in a little hot water and filter4 ,the shade of color is proportional to the amount of caramel present4 ,to verify the test1 pour the colored fluid into a freshly prepared solution of phenylhydrazin 7#b parts phenylhydrazin-hydrochlorid1 #c parts sodium acetate1 and #bj parts water74 ,much caramel produces a dark-brown precipitate in the cold1 and is hastened by slightly heating4 ,a very small amount of caramel will require several hours to precipitate4 ,,apple-,,juice ,,in ,,jellies ,,made ,,of ,,small ,,fruits ,very often cider is added to other fruit juices to give them the proper consistency in jellies1 jams1 and marmalades4 ,its presence may some times be determined by making the usual starch test4 ,a large quantity of starch is normally present in apples1 but is less as they ripen1 and finally disappears in the ripened fruit4 ,there is no starch1 or only a mere trace1 in small fruits even when green4 ,it is readily seen that if the juice is taken from green apples that there will be starch found in the artificial jelly or jam1 though its absence does not prove the absence of cider4 ,make the starch test as follows3 ,,starch ,,in ,,jellies1 ,,jams1 ,,and ,,such ,,products ,make a solution of the jelly or jam and destroy the color by heating nearly to the boiling point and adding dilute 7#a 3 #c7 sulfuric acid and potassium permanganate until the color is destroyed4 ,this treatment does not affect the starch1 and when cool add iodin1 preferably potassium iodid-iodin 7potassium iodid1 #j4d gram2 iodin1 #j4a gram2 water1 #bj cc474 ,if a great quantity of starch is present an almost black precipitate will be formed4 ,smaller amounts give the usual blue color4 ,whenever starch is found to be present1 it is best to make a microscopical examination in the case of jams and marmalades4 ,if the starch is normally present the grains will be seen within the cell walls after the iodin treatment4 ,starch is nearly always present in the apple and some other fruits1 so unless it is present in jelly and such products in considerable quantity it is not likely that it was added4 ,,gelatin ,,in ,,jellies ,henzold ,test4--,add water to some of the jelly and boil for a short time1 filter and treat the filtrate with an excess of a #aj per cent solution of potassium bichromate and boil again4 ,after cooling add #b or #c drops of concentrated sulfuric acid4 ,a white flocculent precipitate forms if gelatin is present1 and it gradually collects in a lump at the bottom4 ,e4 ,beckmann's ,method4--,treat the jelly with #ie per cent alcohol and wash the precipitate with alcohol to free it from the sugar1 then drive off the alcohol by heating4 ,add a very little water to the residue and neutralize the extract with calcium carbonate4 ,then add formalin and evaporate to dryness4 ,by this treatment gelatin is rendered insoluble4 ,pure fruit jellies have only #a to #b per cent of insoluble precipitate1 while those jellies in which gelatin is used have #gj to #hf per cent of insoluble precipitate4 ,,agar ,,agar ,boil the sample with #e per cent sulfuric acid4 ,add a crystal or two of potassium permanganate1 and wait till it settles1 and examine the sediment for diatoms with a microscope4 ,their presence shows the use of agar4 ,,heavy ,,metals ,,tin1 ,,zinc1 ,,lead1 ,,and ,,copper ,a4 ,h4 ,allen's ,method4--7,see test for heavy metals under canned meat47 ,,arsenic ,marsh's ,test4--,fit a #ajj cc4 flask with a two-holed rubber stopper1 through which passes a long-stemmed separatory funnel reaching nearly to the bottom1 and a delivery tube which connects with a bulb tube containing a little acetate of lead solution4 ,this in turn is connected with a calcium chlorid tube and this with a small1 hard glass tube1 #ae or #bj cm4 long1 not over #j4e cm4 bore1 and drawn to small size in the middle4 ,the large part next the chlorid tube is protected by fine wire gauze which extends to within a half inch of the constricted part4 ,two burners may be so placed as to heat the gauze4 ,the flask should be placed in water and the bulb tube may be4 ,four grams of arsenic-free zinc1 and #dj cc4 of dilute pure sulfuric acid 7#a to #h7 are placed in the flask4 ,let the hydrogen flow at least a quarter of an hour1 then heat the gauze for #ae or #bj minutes4 ,there should be no deposit in the tube4 ,now1 char a portion of the sample1 dissolve in water and pour into the separatory funnel1 letting it run slowly into the flask4 ,a dark deposit in the glass tube shows that arsenic is present1 but if after an hour no darkening takes place it is quite safe to say that no arsenic is present in the fruit4 ,illustration3 ,apparatus for ,marsh ,test ,gutzeit's ,test4--,place a gram of pure zinc1 #e cc4 of dilute sulfuric acid 7#f per cent7 and about #a cc4 of a solution of the sample in a deep test tube4 ,cover the tube with three thicknesses of filter paper1 fitted tightly over the mouth of the tube4 ,place on the upper paper a drop of strong silver nitrate solution4 ,place the tube in a dark place and leave for #aj minutes4 ,if a bright yellow stain forms on the filter paper1 and turns black or brown when water is added to it1 arsenic is present4 ,unless one is certain of the purity of the reagents used it is advisable to make a blank test1 using distilled water instead of the fruit4 ,oxidize all sulfids to sulfates before applying the above test4 ,to find out whether they are present or not1 substitute lead acetate for the silver nitrate on the filter paper4 ,to avoid some of these difficulties treat according to the following method3 ,preparation of the sample according to ,leach4--,if possible reduce the sample to a dry char by treatment with concentrated nitric and sulfuric acids so that it may be powdered in a mortar4 ,dissolve out the arsenic by repeated treatment with boiling water4 ,save this extract1 and1 when cool1 filter and submit to ,marsh's test which is given above4 ,in case the sample is too much of a solid to get the arsenic out by the above treatment1 it may be prepared according to the directions of ,chittenden and ,donaldson3 ,heat #ajj grams of the macerated sample with #bc cc4 of pure1 strong nitric acid to a temperature of #aej ,c4 or #afj ,c4 ,assist the action by stirring occasionally4 ,when the fruit becomes a deep yellow or orange color1 remove the heat and add #c cc4 of pure1 strong sulfuric acid4 ,it should be stirred while nitrous fumes are passing off4 ,heat again to about #ahj ,c41 and before it cools add1 drop by drop1 #h cc4 of pure concentrated nitric acid4 ,it should be stirred constantly while the acid is being added4 ,heat at #bjj ,c4 till sulfuric acid fumes begin to come off and only a dry mass remains4 ,powder the mass and exhaust it with boiling water1 filter and test the solution when cold with ,marsh's test4 ,,chapter ,,vii ,,flavoring ,,extracts ,,lemon ,,extract ,the important ingredients of lemon extract are lemon oil and citral1 its aromatic constituent4 ,oil of citronella and oil of lemon grass are sometimes substituted for lemon oil4 ,methyl alcohol is sometimes used in place of the more expensive spirit alcohol as a solvent for the lemon oil4 ,,lemon ,,oil ,the presence of lemon oil may be detected by adding a large excess of water to a small amount of the extract in a test tube4 ,if the mixture does not show some cloudiness1 it is a strong indication that no lemon oil is present4 ,the degree of cloudiness gives an idea of the amount of oil present4 ,,citral ,this is present in the oil of lemon grass1 which is sometimes used as a substitute for lemon oil4 ,citral may be detected by the following test by ,burgess3 ,add #bj cc4 of sulfuric acid to #he cc4 of water4 ,dissolve in this mixture #aj grams of mercuric sulfate4 ,shake #b cc4 of the sample with #e cc4 of this reagent in a test tube4 ,if citral is present1 the liquid will be bright red1 and will quickly disappear and give place to a whitish compound1 which floats on top4 ,,oil ,,of ,,citronella ,this is often substituted for lemon oil4 ,it may be detected by the same test which was used for citral4 ,instead of the red color and the white compound1 citronella gives a bright yellow color1 which does not disappear for some time4 ,,tartaric ,,or ,,citric ,,acid ,precipitate the oil by the addition of an equal volume of water4 ,filter and add a very little of the filtrate to a test tube nearly full of cold lime water4 ,a precipitate will form if tartaric acid is present and it will dissolve in an excess of ammonium chlorid or acetic acid4 ,filter1 or1 in case no precipitate forms1 heat the liquid4 ,citric acid is precipitated in the presence of a large excess of hot lime water4 ,,methyl ,,alcohol ,mullikin and ,scudder4--,take #b ft4 of ,no4 #ab-ae copper wire and bend at right angles about #h or #aj inches from one end4 ,grasp this bent end and an ordinary lead pencil side by side in such a way that the bend will be about the middle of the pencil4 ,wind the wire around the pencil and toward the free end of the short part of the wire until you have a coil #c or #d cm4 long4 ,remove the pencil and twist the unwound parts together for a handle for the coil4 ,dilute a portion of the sample #c or #d times1 and oxidize #aj cc4 of the diluted liquid 7preferably in a test tube7 by heating to a red heat the above copper coil in the oxidizing flame of a ,bunsen lamp4 ,thrust the heated coil quickly into the liquid contained in the test tube4 ,in a second withdraw and immerse in water4 ,continue this operation till the oxid of copper fails to be reduced 7usually #d or #e times is sufficient74 ,cool the liquid by immersing the tube in water4 ,separate into two parts and test each for formaldehyde by the following methods3 ,mullikin1 ,s4 ,p4--,place one of these parts in an evaporating dish1 and add to it #a cc4 of strong ammonia1 boil gently over the free flame till the vapors cease to smell of ammonia4 ,add #b or #c drops of strong hydrochloric acid and heat just to boiling1 and cool quickly by dipping the dish in cold water4 ,make the test for formaldehyde3 ,add a drop of a solution of resorcin 7#a 3 #bjj7 and pour this mixture slowly down the side of an inclined test tube which contains #c cc4 of strong sulfuric acid1 taking care to keep the liquids separate4 ,after #c minutes give the tube a rotary motion by rolling between the hands for a minute or more but only gradually mixing the water and acid1 but mixing only about half of the acid4 ,flecks of a rose-red color form if methyl alcohol is present4 ,bands of color or flecks of other colors1 even though they be tinged with red or a rose-red solution without the precipitate1 should never be taken as proof that methyl alcohol is present4 ,these conditions1 however1 are good grounds for repeating the test2 #aj per cent or even less may be detected by this test4 ,hydrochloric ,acid and ,ferric ,chlorid ,test4--,add a few drops of the other part of the above oxidized liquid to about #aj cc4 of milk1 known to be free from formaldehyde1 in a porcelain casserole1 and add #aj cc4 of commercial hydrochloric acid 7sp4 gr4 #a4b7 which contains #a cc4 of #aj per cent ferric chlorid per #ejj cc4 ,heat slowly over the open flame nearly to boiling4 ,give the liquid a rotary motion to break up the curd4 ,if formaldehyde is present1 the liquid will be colored violet4 ,if not1 it slowly turns brown4 ,the presence of formaldehyde proves that methyl alcohol was in the original extract4 ,,coloring ,,matter ,preliminary ,test4--,treat the sample with strong hydrochloric acid1 and if tropolin or methyl orange be present the solution will turn pink2 ,martius yellow partially decolorizes the solution2 dinitrocresols decolorizes the solution4 ,turmeric or naphthol yellow produces no color change4 ,,turmeric ,turmeric may be detected by soaking a piece of filter paper in the sample1 drying and dipping it in a dilute solution of boric acid or borax which has been slightly acidulated with hydrochlorid acid4 ,dry again and a cherry-red color forms if turmeric is present4 ,add a drop of dilute alkali and if turmeric be present the paper will be colored dark olive4 ,,coal-,,tar ,,colors ,evaporate some of the extract to dryness2 take up the residue with water and extract the coal-tar colors if present1 and test for them by the method given under canned vegetables4 ,,vanilla ,,extracts ,the best grades of vanilla extract are made by treating vanilla beans with #ej per cent alcohol4 ,coumarin1 an extract from tonka beans1 may be used in making the extract4 ,this of course would make a cheaper product4 ,if less than #ej per cent alcohol is used in making the extract1 some alkali must be added to dissolve the resins which will not dissolve in a weaker alcohol4 ,in artificial extracts some such coloring matter as caramel or tannin is used4 ,preliminary ,test4--,to a portion of the extract add a few drops of lead acetate solution4 ,the absence of a bulky flocculent precipitate shows the extract not to be of high quality4 ,leach recommends that normal acetate of lead be added to the sample1 and if a precipitate does not form it is conclusive evidence that it is not a pure extract4 ,when a precipitate forms with the above reagent1 it should settle immediately and leave a clear and almost colorless liquid4 ,when there is a mere cloudiness only1 it may be due to caramel1 in which case the extract is to be suspected4 ,,alkali ,shake a portion of the sample with twice its volume of water4 ,if no precipitate forms1 an alkali is present4 ,a flocculent reddish-brown precipitate shows no alkali is present4 ,if the solution is milky it indicates the presence of a foreign resin4 ,add hydrochloric acid drop by drop to the diluted extract4 ,nothing more than a mere turbidity should result4 ,should it be quite turbid and the color fading after a time1 it shows that an alkali has been used4 ,,foreign ,,resins ,mix a portion of the extract slowly with twice its volume of water1 frequently shaking the mixture4 ,when this solution is milky1 it indicates a foreign resin4 ,hess' ,test4--,dealcoholize #be cc4 of the sample by concentrating on the water-bath1 adding water from time to time to retain the original volume4 ,when no alkali is present in the extract1 pure vanilla resin will be thrown down as a reddish-brown flocculent precipitate4 ,collect the resin1 whatever its color1 on a filter1 and wash4 ,save the filtrate to test for caramel4 ,place a piece of the paper and resin in a dilute solution of potassium hydroxid4 ,if the resin is that of pure vanilla it will dissolve1 giving a deep-red color1 and is reprecipitated when the alkali is neutralized with hydrochloric acid4 ,dissolve another part of the precipitate in alcohol1 and to a part of this solution add a few drops of ferric chlorid2 and to the other part1 hydrochloric acid4 ,there should be no marked coloration in either case if the resin is that of pure vanilla4 ,foreign resins nearly always produce a coloration4 ,,caramel ,shake the bottle of vanilla1 and if the bubbles1 which form1 are a bright caramel color1 keeping the color till all are gone1 the presence of caramel is indicated4 ,concentrate a portion of the filtrate1 which was saved in making the test for foreign resins1 at a rather low temperature until it has about the same color as the original extract4 ,add a few drops of strong hydrochloric acid and heat very gently4 ,if caramel is present1 a yellowish-red flocculent precipitate will form4 ,after the liquid cools1 filter and wash with water4 ,should this precipitate contain caramel1 it will not dissolve in water1 ether1 and alcohol1 but will dissolve in sodium hydroxid1 dilute alcohol1 and glacial acetic acid4 ,,tannin ,test another portion of the filtrate made in testing for foreign resins1 with a few drops of a solution of gelatin4 ,a slight precipitate only should form due to the presence of a small amount of tannin normally present in this filtrate4 ,a large excess shows that it has been added to the extract4 ,,coumarin ,leach's ,test4--,dealcoholize a portion of the sample as above and treat with ammonia1 add #c or #d volumes of chloroform in a separatory funnel4 ,evaporate the chloroform extract in an oven1 not permitting the temperature to rise above #fj ,c4 ,to the residue add a few drops of water2 warm gently1 and add a little of a solution of #a gram of crystallized potassium iodid in #ej cc4 of water1 and the solution saturated with iodin4 ,if coumarin is present1 a brown1 precipitate will form1 and if stirred with a rod it will collect in dark green flecks4 ,,chapter ,,viii ,,saccharine ,,products ,,honey ,bees are sometimes fed with cane sugar4 ,often glucose syrup is poured over honeycomb from which the honey has been extracted1 and the mixture sold as genuine honey4 ,gelatin may be added to increase the weight or to thicken the more voluble adulterants4 ,the ash of genuine honey is not over #j4c per cent4 ,whenever the ash is greater than this it should be tested for calcium sulfate1 the presence of a considerable quantity of which is an almost certain proof that starch glucose or invert sugar has been added to the honey4 ,sulfates may be detected by adding barium chlorid to the aqueous solution of the honey and precipitating barium sulfate4 ,if the ash is high and considerable chlorids are present1 molasses has quite probably been added to the honey4 ,the presence of chlorids may be determined by the addition of silver nitrate which precipitates silver chlorid4 ,,cane ,,sugar ,the presence of cane sugar can be detected with certainty only by the use of the polarimeter4 ,its presence in large quantity gives a high right-handed rotation4 ,,commercial ,,glucose ,,syrup ,allen's ,test4--,make the test for dextrine which is present in commercial glucose1 but not in pure honey4 ,dilute a portion of the honey with an equal volume of water and add methyl alcohol with constant stirring until there is a permanent turbidity4 ,if glucose syrup is present a heavy gummy precipitate will soon form4 ,genuine honey gives only a slight milkiness4 ,,gelatin ,dilute a portion of the sample and add a solution of tannic acid4 ,a precipitate indicates the presence of gelatin4 ,treat the sample with alcohol1 and gelatin1 if present1 will be left undissolved1 and it will give its characteristic odor on ignition4 ,,maple ,,syrup ,this is sometimes adulterated with glucose1 molasses1 golden syrup1 and with ordinary white sugar4 ,there are no satisfactory simple chemical tests for these substances4 ,pure maple syrup should have an ash not lower than #j4ce to #j4dj per cent4 ,a lower ash shows that cane sugar has been added4 ,a higher ash would indicate the presence of molasses or brown sugar stock4 ,these last two adulterants1 if present in great abundance1 may be detected by taste4 ,,glucose ,this may be detected by the use of the polarimeter4 ,pure maple syrup gives #ec4a to #fj direct1 and--#bb4b to--#ba4i after hydrolysis4 ,maple syrup adulterated with glucose gives #hj to #ajj direct and #ah4i to #de4f after hydrolysis 7according to ,ogdon74 ,,chapter ,,ix ,,spices ,,mustard ,mustard is often adulterated with mustard hulls1 wheat1 and rice4 ,and when white-colored flour of any kind is used1 turmeric1 ,martius yellow1 or a coal-tar color is employed to give the mixture the color of mustard4 ,cayenne pepper is occasionally used to impart pungency to diluted mustard4 ,,flour ,boil #b grams of the mustard in #d or #e cc4 of distilled water for about #aj minutes4 ,after it is cool1 add a few drops of iodin solution slowly1 avoiding a large excess though having a little uncombined iodin4 ,if a blue color is produced1 some starchy matter has been added to the mustard4 ,the intensity of the reaction is an indication of the amount of starchy matter used4 ,pure mustard contains no starch and hence gives no reaction with iodin4 ,,coloring ,,matter ,pure mustard is a very light dull yellow1 and whenever the sample is bright yellow1 there is good grounds for suspecting the presence of some artificial coloring matter4 ,,turmeric ,add strong ammonium hydroxid to the mustard1 and if turmeric is present an orange-red color is usually produced4 ,make an alcoholic extract of the sample and dip a piece of filter paper in it1 and when dry draw it through a cold1 saturated solution of boric acid in water4 ,an orange or red-brown tint produced on the paper indicates the presence of turmeric4 ,thoroughly mix #b or #c grams of the mustard with castor oil and filter4 ,if turmeric is present the filtrate will appear fluorescent4 ,extract a portion of the sample with #c times its weight of wood alcohol and filter4 ,evaporate one half of the solution to dryness and add a little hydrochloric acid to the residue4 ,this will turn red whenever turmeric is present1 and if an excess of alkali be added it will change to a greenish blue4 ,evaporate the other half to dryness and moisten with a solution of boric acid and dry on a steam bath4 ,a cherry-red color indicates turmeric4 ,,martius ,,yellow ,,or ,,analogous ,,coal-,,tar ,,coloring ,,matter ,extract the slightly acidified sample with #ie per cent alcohol and dye wool as directed under 8,vegetables40 ,the wool will be dyed a bright yellow4 ,allen's ,test4--,treat a portion of the sample with cold alcohol1 and shake vigorously for #e minutes1 then filter and evaporate the filtrate to dryness2 add enough water to take up the residue and dye some white wool in this liquid as in the last test4 ,when the dyed wool is wrapped in white paper and heated to #abj in an air bath1 part of the coloring matter will be transferred to the paper4 ,the coloring matter dissolves readily in dilute ammonia or hot water1 and on the addition of hydrochloric acid the solution is decolorized and a yellow precipitate formed4 ,this distinguishes it from picric acid4 ,,cayenne ,,pepper ,allen's ,test4--,boil #a gram of the mustard for a few minutes with alcohol1 filter1 and evaporate to dryness at about #ajj4 ,taste the residue and cayenne may be recognized by its pungency4 ,or heat a portion of the extract1 and smell the fumes4 ,irritation of the lungs and coughing will surely follow if cayenne pepper is present4 ,,pepper ,pepper may be adulterated with wheat1 buckwheat1 pepper husks1 ground olive stones1 spent ginger4 ,cayenne pepper is sometimes added to adulterated pepper to give it the normal pungency4 ,many of these adulterants can be detected only by the aid of the microscope4 ,neuss's ,test4--,true pepper turns an intense yellow when covered with strong hydrochloric acid4 ,any adulteration can be detected at once by the color4 ,,ground ,,olive ,,stones ,,or 8,,poivrette0 ,make a paste of the pepper with caustic alkali4 ,dilute with a large quantity of water and wash by decantation4 ,olive stones will be colored a bright yellow2 pepper-husks will appear dark4 ,jumeau's ,test4--,dissolve #e grams of iodin in a mixture of #ej cc4 of ether and #ej cc4 of alcohol4 ,cover the bottom of a porcelain capsule with the finely ground pepper1 and add just enough of the iodin mixture to wet the entire mass1 and mix well till it has the same consistency throughout4 ,let dry in the air1 then powder and examine it1 and if olive stones are present they will be colored yellow4 ,pure pepper would have a deep brown color4 ,aniline acetate1 one part aniline in #c parts acetic acid1 colors pure pepper gray or white and olive stones yellowish brown4 ,,cayenne ,heat some of the red particles found in the pepper and their characteristic vapor is produced4 ,dissolve the particles in alcohol or ether and the same vapors are produced4 ,,chapter ,x ,,vinegar ,vinegars may be adulterated by the addition of mineral acids as sulfuric or hydrochloric4 ,caramel or the coal-tar dyes may be employed to improve the color or to give color to an artificial product4 ,malic acid is always present in cider vinegar4 ,potassium acid tartrate occurs in true wine vinegar4 ,poisonous metals may be present in vinegars containing free mineral acid4 ,entirely artificial cider vinegar is often found on the market4 ,,preparation ,,of ,,the ,,sample ,,for ,,testing ,if the vinegar is turbid from any suspended matter1 it should be filtered4 ,the samples should be analyzed at once1 and in the laboratory they should always be kept in glass-stoppered bottles4 ,general ,observations4--,ignite a little of the vinegar residue on a clean platinum wire in a colorless ,bunsen flame1 and if it is pure cider vinegar the flame will be colored the characteristic lilac color of potassium4 ,the sodium flame is absent or only a mere trace of it is present4 ,but in all artificially colored vinegars1 spirit sugar and glucose vinegars1 the sodium flame predominates4 ,the residue of cider vinegar is thick1 viscid1 or mucilaginous1 of a light brown color1 astringent acid taste though not unpleasant4 ,the solids of sugar-house vinegar1 those from colored spirit and wood vinegar1 each have a bitter taste on account of the caramel used to color them4 ,the residue of the sugar-house vinegar has the odor of molasses4 ,wood vinegar when present gives a residue with a tarry or smoky taste and smell4 ,glucose vinegar gives the odor of scorched corn4 ,solids of fruit vinegars are quite soluble in alcohol1 except a granular residue in grape vinegar1 while the solids of malt and glucose vinegars are almost insoluble4 ,the ash of fruit vinegars and malt vinegars has a distinct alkaline reaction1 while that of spirit and wood vinegars is very feebly alkaline4 ,,free ,,mineral ,,acids ,the ash of pure cider vinegar is always alkaline4 ,if a vinegar should show a neutral reaction this would certainly indicate the presence of a free mineral acid4 ,if the ash be alkaline1 no acid except nitric could have been present1 and this is seldom1 if ever1 used as an adulterant of vinegar4 ,,when ,,the ,,ash ,,is ,,alkaline ,,apply ,ashby's ,test4--,extract #j4e gram of logwood in #ajj cc4 of water and dry a drop or two on a porcelain surface4 ,then add a drop of the vinegar and dry again4 ,if the residue is red1 a mineral acid is present2 if yellow1 mineral acids are absent4 ,when only a very small amount of the acid is present the red coloration will be destroyed on diluting with water1 but may be restored by concentrating the liquid4 ,,sulfuric ,,acid ,sulfuric acid1 if present1 will cause the vinegar to leave a charred mass when evaporated over the water-bath4 ,frear's ,method4--,mix #e cc4 of the sample and #e or #aj cc4 of water1 and add a very little of a solution of methyl violet 7made by dissolving one part of methyl violet #b ,b4 in #ajj1jjj parts of water74 ,a blue or green coloration shows the presence of mineral acids4 ,,sulfuric ,,acid ,,as ,,distinguished ,,from ,,sulfates ,allen's ,method4--,evaporate #ajj cc4 of the vinegar down to one tenth its volume1 and when cold add #ej cc4 of alcohol4 ,sulfuric acid remains in solution while the sulfates are precipitated4 ,dilute the solution and precipitate the acid with barium chlorid4 ,,hydrochloric ,,acid ,,free ,place a definite quantity of the vinegar in a distilling flask and distil off half4 ,add a few drops of silver nitrate to the distillate4 ,if a precipitate forms1 hydrochloric acid is present4 ,,malic ,,acid ,leach's ,method4--,to #e cc4 of the sample1 add a few drops of a solution of calcium chlorid 7#a 3 #aj72 make slightly alkaline with ammonia4 ,filter off any precipitate that may form1 add #bj to #cj cc4 of #ie per cent alcohol to the filtrate and heat to boiling4 ,if malic acid is present1 a voluminous flocculent precipitate will form4 ,a precipitate may form in vinegars containing dextrine4 ,make a further test for malic acid by the following3 ,filter and treat the precipitate with a little alcohol1 and when dry add concentrated nitric acid and evaporate to dryness on a water-bath4 ,treat the residue with sodium carbonate1 boil for a short time1 filter4 ,add acetic acid to the filtrate till slightly alkaline1 boil till carbon dioxid is expelled1 and if on the addition of calcium sulfate a precipitate forms1 it indicates the presence of malic acid4 ,,coloring ,,matter ,,caramel ,the residue of vinegar to which much caramel has been added has an unusually dark color and bitter taste4 ,crampton and ,simons' ,method4--,shake well together in a corked flask #ej cc4 of the vinegar with about half as many grams of fullers' earth2 after standing for half an hour filter4 ,vinegar containing no artificial color will show scarcely any change in color when thus treated4 ,a caramel-colored vinegar will be decolorized in proportion to the amount of caramel present4 ,,coal-,,tar ,,colors ,,in ,,wine ,,vinegar ,test by the usual test for coal-tar dyes4 ,see under canned vegetables4 ,,metallic ,,impurities ,vinegars containing free mineral acids are sometimes found to contain poisonous metals4 ,evaporate #bjj to #djj cc4 of the vinegar to dryness1 add a little sodium hydroxid to this residue and burn to an ash over a low flame4 ,it may be necessary to add a little potassium nitrate once or twice4 ,add a little dilute hydrochloric acid and saturate with hydrogen sulfid and test for lead1 zinc1 copper1 and arsenic according to ,allen's method given under canned meats4 ,,spices ,,to ,,increase ,,pungency ,leach4--,neutralize a portion of the vinegar with sodium carbonate4 ,the presence of spices is easily detected by tasting this mixture4 ,another ,test4--,exactly neutralize a little of the vinegar as above1 evaporate to smaller bulk and taste as before1 then shake the concentrated liquid with ether1 separate the ethereal layer and evaporate it1 and taste the residue4 ,,tartar ,,in ,,wine ,,vinegar ,the presence of tartar in vinegar proves it to be wine vinegar4 ,allen's ,method4--,evaporate a portion of the vinegar and treat the residue with alcohol2 a granular residue of tartar remains undissolved4 ,to prove that it is tartar1 decant the alcohol and dissolve the residue in a little hot water1 cool1 rub the inside of the vessel with a glass rod1 and if tartar was present acid potassium tartrate will be deposited where the rod touched the vessel4 ,the test will be more sensitive if an equal volume of alcohol is added4 ,,free ,,tartaric ,,acid ,,in ,,wine ,,vinegar ,test as for ,tartar4--,treat the alcoholic solution of the extract with an alcoholic solution of potassium acetate4 ,rub the sides of the vessel as before1 and if tartaric acid is present the streaks and sometimes a precipitate forms where the rod touches the vessel4 ,,glucose ,glucose is present when both direct and invert readings are dextro-rotatory4 ,,chapter ,,xi ,,fats ,,and ,,oils ,,lard ,lard is very often adulterated with cottonseed oil1 cottonseed stearin and beef stearin4 ,their being very much cheaper accounts for the sophistication4 ,,cottonseed ,,oil ,halphen's ,test4--,dissolve #a per cent of sulfur in a given volume of carbon bisulfid4 ,add an equal volume of amylic alcohol4 ,mix #c to #e cc4 of this reagent with an equal volume of the melted lard in a test tube4 ,close with a cotton stopper and boil for #ae minutes in a bath of saturated brine4 ,the presence of cottonseed oil is indicated by a deep-red or orange color1 little or no color resulting in its absence4 ,lard from hogs fed on any of the various cottonseed products may give a faint reaction when this test is applied4 ,,cottonseed ,,stearin ,since cottonseed stearin is only the more solid portions of cottonseed oil1 the above test may be applied1 but to distinguish it from the latter it is necessary to make determinations quite beyond the scope of this set of tests4 ,,beef-,,stearin ,it is very difficult to identify beef-stearin by chemical tests4 ,it is usually detected by use of the microscope4 ,leach gives the following method3 ,make a solution of #b to #e grams of the fat in #aj to #bj cc4 of ether4 ,let stand a half day1 at about the room temperature4 ,loosely stopper the tube with cotton to prevent too rapid evaporation of the ether4 ,it is well to vary the conditions of heat1 amount of solvent1 and rate of crystallization1 to get the best possible results4 ,it may often be well to separate the crystals thus obtained by filtering and recrystallizing from ether4 ,separate the crystals that form at the bottom of the test tube from the liquid portion by pouring on a small filter4 ,wash them several times with ether1 but not sufficient to remove the mother liquor entirely4 ,in case it is all removed1 and the crystals are too fragile to mount1 add a drop of alcohol4 ,crystals of lard stearin are flat rhomboidal plates1 one end being oblique to the sides1 and they do not appear to be regularly grouped4 ,beef-stearin crystals are rod-shaped1 or needles often apparently curved with pointed ends1 and are arranged in clusters like the ribs of a fan1 the crystals radiating from a common point4 ,under certain conditions the lard crystals are not irregularly grouped1 but are arranged like the parts of a feather1 where one part seems attached to another close at hand4 ,considerable experience is necessary to use this test with absolute certainty4 ,,olive ,,oil ,olive oil is one of the most commonly adulterated foods4 ,the commonest adulterant probably is cottonseed oil4 ,other foreign oils1 such as peanut1 sesame1 and rape1 are sometimes used4 ,preliminary ,test4--,pure olive oil turns from a pale to a dark-green color in a few minutes1 when it is shaken with the same volume of concentrated nitric acid or sulfuric acid4 ,whenever a reddish to an orange1 or brown coloration results1 the presence of a foreign vegetable oil is indicated 7probably a seed oil74 ,bach gives the following results of strong nitric acid on the common oils4 ,olive oil when shaken with nitric acid gives a pale green1 which changes to an orange yellow after heating five minutes4 ,with similar treatment peanut oil gives pale rose and brownish yellow2 rape oil1 pale rose and orange yellow2 sesame oil1 white and brownish yellow2 sunflower oil1 dirty white and reddish yellow2 cottonseed oil1 yellowish brown and reddish brown2 castor oil1 pale rose and golden yellow4 ,pontet's ,test2 ,elaiden ,test4--,treat #a cc4 of mercury with #ab cc4 of cold nitric acid 7sp4 gr4 #a4db7 and shake #b cc4 of this freshly-made solution with #ej cc4 of the sample in a bottle every #aj minutes for #b hours4 ,oils which are principally olein1 or mixtures of olein and solid esters like palmatin and stearin1 give more or less solid products1 but olive oil is remarkable for the firmness of the canary or lemon-yellow mass which is formed4 ,after standing a day the mass cannot be pierced with a glass rod and sometimes it gives forth a sound when struck4 ,this test requires considerable experience to be used with any great degree of certainty4 ,,cottonseed ,,oil ,carbon bisulfid containing #a per cent of sulfur in solution is mixed with an equal amount of amyl alcohol4 ,equal volumes 7about #c cc47 of this reagent and the sample1 are mixed in a test tube1 which is loosely stoppered with cotton1 and heated in a bath of boiling saturated brine for a quarter of an hour4 ,the presence of cottonseed oil is shown by the formation of a deep-red or orange color4 ,little if any color is produced in its absence4 ,if no color is produced it is well to add another cc4 of the reagent and heat #e or #aj minutes more1 and to repeat this again if no color forms4 ,lard and lard oil from animals fed on cottonseed meal may give a faint reaction4 ,,peanut ,,oil 7,,arachis ,,oil7 ,bellier's ,test4--,saponify a gram of the sample with #e cc4 of a solution of #he grams potassium hydroxid in a liter of strong alcohol4 ,this may be done in a small ,erlenmeyer flask on the water-bath4 ,then boil for two minutes1 neutralize exactly with dilute acetic acid 7use phenolphthalein as the indicator74 ,cool the mixture by placing the flask in water at #ag to #ai ,c4 ,a precipitate usually forms4 ,add #ej cc4 of #gj per cent alcohol which contains one per cent by volume of concentrated hydrochloric acid 7sp4 gr4 #a4b74 ,shake the flask vigorously and cool again as before4 ,if no precipitate forms the oil is not adulterated with peanut oil4 ,the presence of #aj per cent or more of peanut oil produces a precipitate1 even a smaller amount will produce a cloudiness after standing between #ag and #ai ,c4 for #cj minutes4 ,some varieties of olive oil from ,tunis give the same turbidity when the #gj per cent alcohol is added4 ,to distinguish these from peanut oil heat the mixture on the water-bath till everything has dissolved1 and cool to #ag to #ai4 ,the cloudiness will not appear if the oil is pure1 but will reappear if peanut oil is present4 ,,sesame ,,oil ,badouin's ,test4--,about #j4a of a gram of cane sugar is dissolved in #aj cc4 of hydrochloric acid 7sp4 gr4 #a4bj7 shaken vigorously with #bj grams of the sample for a minute or more4 ,after standing for a while the aqueous solution will separate from the oil4 ,if #a per cent or more of sesame oil is present1 the aqueous solution will be colored crimson4 ,tocher's ,test4--,dissolve #a gram of pyrogallic acid in #ae cc4 of strong hydrochloric acid4 ,add an equal volume of the oil in a separatory funnel4 ,when it has stood a minute1 draw off the aqueous solution and boil4 ,in the presence of sesame oil it is colored red by transmitted light1 and blue by reflected light4 ,,rape ,,oil ,palas' ,test4--,make a #a per cent solution of fuchsin and a #cj per cent solution of sodium acid sulfite4 ,mix together #bj cc4 of each of these solutions and add #bjj cc4 of water and #e cc4 of strong sulfuric acid4 ,after the solution is decolorized1 #aj cc4 of the sample is shaken with it4 ,if rape oil is present1 the color will be partially restored4 ,to prevent the formation of the color by contact with the air have the vessel full of the mixture4 ,,chapter ,,xii ,,beverages ,,coffee ,coffee is often colored with such substances as ,scheele's green1 chrome yellow1 iron oxide1 ,prussian blue1 indigo and turmeric4 ,imitation coffee beans have been made of wheat flour1 bran1 rye1 chicory and peas4 ,allen's ,preliminary ,test4--,a good preliminary test for ground coffee is to sprinkle some of it on the surface of cold water4 ,the oil of true coffee prevents the particles from being readily soaked1 and so they float for some time4 ,chicory and most of the other adulterants of coffee contain no oil1 but do contain caramel1 which is quickly extracted by the water producing a zone of brown color about such particles4 ,they become soaked and quickly sink4 ,the liquid containing pure coffee diffuses uniformly without coloring the water to any perceptible degree4 ,chicory and similar roots give a dark brown1 turbid infusion4 ,roasted cereals do not impart so distinct a color to water4 ,,coloring ,,matter ,shake the coffee beans in cold water and make the regular qualitative tests for the inorganic coloring matters--,scheele's green may be identified by testing for copper and arsenic2 chrome yellow1 by testing for lead chromate2 iron oxide may be detected by its characteristic tests4 ,organic coloring matter is best extracted with alcohol4 ,prussian blue may be detected by dissolving it from the sediment with hot caustic alkali1 acidifying with hydrochloric acid1 treating it with a drop of ferric chlorid4 ,if present1 ferric ferrocyanide1 a blue precipitate1 will be formed4 ,indigo is not discharged by sodium hydroxid1 while ,prussian-blue is4 ,it will form a deep blue solution with sulfuric acid4 ,test for turmeric as under mustard4 ,,imitation ,,coffee ,,beans ,most imitation coffee1 as already stated1 is heavier than water4 ,coffee contains no starch1 so the imitation beans made of cereals may be detected by testing for starch4 ,,starch ,allen's ,method4--,boil the coffee in #aj parts of water4 ,when perfectly cold add to it a little sulfuric acid1 then a strong solution of potassium permanganate1 drop by drop1 with constant shaking1 till the liquid is almost decolorized2 strain or decant and add to the solution a solution of iodin4 ,if #a per cent or more of starch is present1 a blue coloration will be produced4 ,,chicory ,rimmington's ,test4--,boil a portion of the sample with water which contains a little sodium carbonate2 decant1 wash and treat the residue with a weak solution of bleaching powder for several hours4 ,the solution will be decolorized4 ,the coffee will be at the bottom as a dark layer while the chicory will be a light layer above it4 ,albert ,smith's ,test4--,boil #aj grams of the sample in #bej cc4 of water2 strain and add basic lead acetate in slight excess4 ,a precipitate forms1 and when it has settled the supernatant liquid will be colorless if the coffee is pure1 but more or less colored if chicory is present4 ,,tea ,tea is adulterated by the substitution of inferior grades for those of better quality1 by the addition of exhausted leaves and foreign leaves1 by the use of coloring matter or 8facing0 such as ,prussian blue1 indigo1 or turmeric to color green tea1 and sometimes graphite to color black tea4 ,foreign astringents 7generally catechu7 are added to conceal the presence of exhausted leaves4 ,an imitation tea1 8lie tea10 is made of the stems and dust with mineral matter1 and some starch or gum to hold these together4 ,,foreign ,,leaves ,though there are several chemical tests for foreign leaves1 none are as satisfactory as a microscopical examination4 ,soften the leaves by soaking in hot water1 unroll carefully and examine with a hand lens or low power of the microscope4 ,compare with a genuine leaf--the shape1 margin1 and venation4 ,,exhausted ,,tea ,,leaves ,sometimes such leaves may be detected by a physical examination4 ,they are often more or less unrolled and broken on the edges4 ,but the only certain way of ascertaining their presence is to determine the soluble ash which is from #b4e to #d per cent in pure tea and usually less than #j4h per cent in exhausted tea4 ,,lie ,,tea ,this imitation tea is easily detected by pouring hot water over the leaves4 ,if they are artificial1 they will break down into the fragments of which they were made4 ,,facing ,organic coloring matter may be detected by the same method used for detecting such colors in coffee4 ,,catechu ,hager's ,test4--,boil a little of the tea in water1 and add to the extract an excess of lead monoxid4 ,if the tea is pure the addition of a solution of silver nitrate produces only a slight grayish precipitate1 but when catechu is present a yellow flocculent precipitate forms4 ,a ,,few ,,of ,,the ,,best ,,books ,,on ,,food ,,analysis ,,allen1 ,a4 ,h41 ,commercial ,organic ,analysis1 #ahih4 ,price1 #bi4ej4 ,,blyth1 ,a4 ,w41 ,foods1 their ,composition and ,analysis1 #aijc4 ,price1 #h4dj4 ,,hassall1 ,a4 ,h41 ,food1 its ,adulterations and the ,methods for their ,detection1 #ahgd4 ,,leach1 ,a4 ,e41 ,food1 ,inspection and ,analysis1 #aije4 ,price1 #g4ej4 ,,leffmann1 ,h41 and ,,beam1 ,w41 ,select ,methods of ,food ,analysis1 #aije4 ,price1 #b4ej4 ,u4 ,s4 ,dept4 of ,agr41 ,bureau of ,chem41 ,bulletin #ac1 ,parts #a-aj1 ,food and ,food ,adulterants1 #ahhg-aijb4 7,some of these are out of print47 ,bulletin #df1 ,methods of ,analysis of ,foods1 #ahii2 ,bulletin #fe1 ,provisional ,methods for the ,analysis of ,foods1 #aijb4 ,,wiley1 ,h4 ,w41 ,foods and their ,adulteration1 #aijg4 ,price1 #d4jj4 ,,chemicals ,the following are the chemicals used in making all the tests in this book4 ,most of these are found in every chemical laboratory4#a ,acetic acid ,ammonium carbonate ,ammonium chlorid ,ammonium hydroxid ,ammonium sulfid ,amyl alcohol ,aniline ,barium chlorid ,barium peroxide ,boric acid ,bromine ,calcium carbonate ,calcium chlorid ,calcium sulfate ,cane sugar ,carbon bisulfid ,castor oil ,chloroform ,diphenylamine ,ether ,ethyl alcohol ,ferric chlorid ,formalin ,fuchsin ,gelatin ,glycerol ,hydrochloric acid ,iodin ,lead acetate 7basic7 ,lead oxide ,lime water ,litmus paper ,logwood chips ,mercury 7metallic7 ,mercury sulfate ,methyl alcohol ,molybdic oxide ,nitric acid 7sp4 gr4 #a4db7 ,oxalic acid ,petroleum spirit ,phenolphthalein ,phenylhydrazine hydrochlorid ,phosphoric acid ,potassium bichromate ,potassium carbonate ,potassium chromate ,potassium ferrocyanid ,potassium hydroxid ,potassium iodate ,potassium iodid ,potassium nitrate ,potassium permanganate ,pyrogallic acid ,resorcin ,silver nitrate ,sodium acetate ,sodium acid sulfite ,sodium carbonate ,sodium chlorid ,sodium hydroxid ,sulfur ,sulfuric acid ,tannic acid ,turmeric paper ,zinc 7arsenic free7 #a ,the more uncommon ones may be obtained from ,eimer and ,amend1 #bje-baa ,third ,avenue1 ,new ,york4 ,,index ,,of ,,authors ,,and ,,tests ,,page ,allen1 ,a4 ,h41 ,heavy metals in fruits and fruit products1 #cg in meat1 #aa in vinegar1 #eh ,sulfuric ,acid 7distinguished from ,sulfates7 in vinegar1 #eg ,tartar in vinegar1 #ei ,amthor1 ,caramel in fruit and fruit products1 #cf ,ashby1 ,free mineral acids in vinegar1 #ef ,beckmann1 ,starch in jellies1 #ch ,bell and ,carter1 ,alum in flour1 #af ,boettger1 ,ergot in rye flour1 #ah ,bornstein1 ,saccharin in canned vegetables1 #bg ,blyth1 ,alum in bread1 #ai ,courley and ,coremon1 ,horseflesh in other meats1 #ad ,ebers1 ,diseased meat1 #ad ,frear1 ,sulfuric acid in vinegar1 #eg ,geisler1 ,coal-tar colors in butter1 #f ,girard and ,dupre1 ,acid magenta in catsups and tomatoes1 #ce ,cochineal in catsups and tomatoes1 #bi ,cochineal in canned vegetables1 #bi ,gutzeit1 ,arsenic in canned fruits1 #ci ,hehner1 ,formaldehyde in milk1 #c ,henzold1 ,starch in jellies1 #f ,hess and ,doolittle1 ,process or renovated butter1 test for1 #di ,kmmerer1 ,sulfurous acid in meat1 #i ,kleeburg1 ,wheat in rye flour1 #ah ,klinger and ,bujard1 ,cochineal carmine in meat1 #ac ,kraemer1 ,corn meal in wheat flour1 #ag ,leach1 ,caramel in milk1 #a ,malic acid in vinegar1 #eg ,salicylic acid in milk1 #d ,salicylic acid in meat1 #aj ,lythgoe1 ,coal-tar colors in milk1 #b ,marsh1 ,arsenic in canned fruits1 #ch ,martin1 ,coloring matter in butter1 #e ,mohler1 ,benzoic acid in meat1 #aj ,benzoic acid in fruit and fruit products1 #cc ,peter1 ,benzoic acid in canned vegetables1 #bh ,richards1 ,mrs41 ,alum in baking powders1 #bb ,rimmington1 chicory in coffee1 #ff ,schmidt1 ,saccharin in canned vegetables1 #bg ,smith1 chicory in coffee1 #ff ,sostegni and ,carpentieri1 ,coal-tar dyes in canned vegetables1 #bi ,stoke1 ,gelatin in milk1 #b ,tocher1 sesame oil in olive oil1 #fd ,vanderplanken1 ,alum in sour bread1 #ai ,vogel1 ,substituted flours1 #ag ,wynter ,blyth1 alum in flour1 #af ,wolff1 ,tartaric acid 7free or combined7 in baking powders1 #bj ,,index ,,page ,acid magenta in fruit and fruit products1 #ce ,agar agar in fruit and fruit products1 #cg ,alkali in vanilla extract1 #de ,allen1 ,a4 ,h41 heavy metals in fruit and fruit products1 #cg in meat1 #aa in vinegar1 #eh sulfuric acid in vinegar1 #eg tartar in vinegar1 #ei test of coffee1 #fe ,alum in baking powders1 #bb in bread1 #ah in flour1 #af in pickles1 #ca ,aluminium salts in cream of tartar1 #bc ,ammonia in cream of tartar1 #bc ,ammonium salts in baking powders1 #ba ,amthor1 caramel in fruit and fruit products1 #cf ,annatto in butter1 #e in milk1 #a ,aniline red in meat1 #ac ,apple juice in jellies made from small fruits1 #cf ,arsenic in fruit and fruit products1 #ch ,ashby1 free mineral acids in vinegar1 #ef ,bach1 test of olive oil1 #fb ,baking powders1 #bj ,adulterations of1 #bj ,alum1 #bb ,ammonium salts1 #ba ,gypsum1 #ba ,sulfates 7calcium1 etc471 #ba ,tartaric acid 7free71 #ba ,tartaric acid 7free or combined71 #bj ,beckmann1 gelatin in jellies1 #ch ,bell and ,carter1 alum in flour1 #af ,beef stearin in lard1 #fa ,benzoic acid in meat1 #aj in canned vegetables1 #bg in fruit and fruit products1 #cd ,blyth1 alum in bread1 #ai ,boettger1 ,ergot in rye flour1 #ah ,borax in fish and oysters1 #ac in meats1 #i ,boric acid in fish and oysters1 #ac in meat1 #i in milk1 #d ,bornstein1 saccharin in canned vegetables1 #bg ,bread1 #ah ,adulterations of1 #ah ,alum1 #ah ,copper sulfate1 #ai ,butter1 #e ,adulterations of1 #e ,coloring matter1 #e ,annatto1 #e ,coal-tar colors1 #e ,marigold1 #f ,saffron1 #f ,turmeric1 #f ,cottonseed oil1 #g ,oleomargarine1 #g ,process or renovated butter1 #f ,cane sugar in honey1 #di ,canned and bottled vegetables1 #bd ,adulterations of1 #bd ,alum in pickles1 #ca ,coal-tar colors1 #bi ,cochineal1 #bi ,coloring matter1 #bi ,copper salts in green pickles1 beans1 peas1 etc41 #cj ,turmeric in mixed pickles1 #cj ,examination of can or box1 #ca ,heavy metals other than copper 7see under meats71 #aa ,preservatives1 #be ,benzoic acid1 #bg ,formaldehyde1 #be ,saccharin1 #bf ,salicylic acid1 #bf ,sulfurous acid1 #bf ,soaked vegetables1 peas1 beans1 and corn1 #cj ,caramel in fruit and fruit products1 #cf in milk1 #a in vanilla extract1 #dg in vinegar1 #eh ,catechu in tea1 #fh ,cayenne pepper in black pepper1 #ed in mustard1 #ec ,cereal products1 #af ,chicory in coffee1 #ff ,citral in lemon extract1 #db ,citric acid in lemon extract1 #dc ,coal-tar colors in butter1 #e in canned vegetables1 #bi in fruit and fruit products1 #ce in lemon extract1 #de in milk1 #b in vinegar1 #eh ,cochineal carmine in canned vegetables1 #bi in fruit and fruit products1 #ce in meat1 #ac ,coffee1 #fe ,adulterations of1 #fe ,chicory1 #ff ,coloring matter1 #fe ,imitation coffee beans1 #ff ,starch1 #ff ,coloring matters ,acid magenta in fruit and fruit products1 #ce ,annatto in butter1 #e in milk1 #a ,aniline red in meat1 #ac ,caramel in fruit and fruit products1 #cf in milk1 #a in vanilla extract1 #dg in vinegar1 #eh ,copper salts in canned vegetables1 #cj ,coumarin in vanilla extract1 #dh ,copper sulfate in bread1 #ai in flour1 #ag ,copper salts in canned vegetables1 #cj ,cottonseed oil in butter1 #g in lard1 #fj in olive oil1 #fb stearin in lard1 #fj ,courley and ,coremon1 horseflesh in other meats1 #ad ,cream of tartar1 #bb ,adulterations of1 #bb ,aluminium salts1 #bc ,ammonia1 #bc ,earthy materials1 #bc ,tartaric acid 7free or combined71 #bb ,dairy products1 #a ,ebers1 diseased meat1 #ad ,eggs1 test for freshness1 #ad ,elaiden test1 #fb ,exhausted tea leaves in tea1 #fg ,facing in tea1 #fh ,fats and ,oils1 #fj ,lard1 #fj ,adulterations of1 #fj ,beef stearin1 #fa ,cottonseed oil1 #fj stearin1 #fj ,olive oil1 #fa ,adulterations of1 #fa ,cottonseed oil1 #fb ,peanut oil1 #fc ,rape oil1 #fd ,sesame oil1 #fd ,fish1 preservatives in1 #ac ,flavoring extracts1 #db ,flour1 #af ,adulterations of1 #af ,alum1 #af ,copper sulfate1 #ag ,substituted flours1 #ag ,corn meal in wheat flour1 #ag ,ergot in rye flour1 #ah ,wheat flour in rye flour1 #ah ,flour in mustard1 #ea ,formaldehyde in canned vegetables1 #be in milk1 #c ,frear1 sulfuric acid in vinegar1 #eg ,fruit and ,fruit ,products1 #cc ,adulterations of1 #cc ,agar agar1 #ch ,apple juice in jellies made from small fruits1 #cf ,arsenic1 #ch ,coloring matter1 #ce ,acid magenta1 #ce ,caramel1 #cf ,coal-tar dyes1 #ce ,cochineal1 #ce ,gelatin in jellies1 #cg ,heavy metals1 #ch ,preservatives1 #cc ,benzoic acid1 #cd ,saccharin1 #cd ,salicylic acid1 #cd ,starch in jellies1 jams1 and such products1 #cg ,gelatin in honey1 #ej in jellies1 #cg in milk1 #b ,geisler1 coal-tar colors in butter1 #f ,ginger cake1 stannous chlorid in1 #ai ,girard and ,dupre1 acid magenta in fruit and fruit products1 #ce cochineal in catsups and tomatoes1 #bi in canned vegetables1 #bi ,glucose in honey1 #ej in maple syrup1 #ej ,gutzeit1 arsenic in canned fruits1 #ci ,gypsum in baking powders1 #ba ,heavy metals in canned vegetables1 #aa in fruit and fruit products1 #ch in meat1 #aa ,hehner1 formaldehyde in milk1 #c ,henzold1 gelatin in jellies1 #cg ,hess and ,doolittle1 test for process butter1 #f ,honey1 #di ,adulterations of1 #di ,cane sugar1 #di ,commercial glucose1 #ej ,gelatin1 #ej ,horseflesh in sausage and mince-meat1 #ad ,hydrochloric acid in vinegar1 #eg test for formaldehyde1 #c1 #be ,imitation coffee beans1 #ff ,kmmerer1 sulfurous acid in meat1 #i ,kleeburg1 wheat in rye flour1 #ah ,klinger and ,bujard1 cochineal-carmine in meat1 #ac ,kraemer1 corn meal in wheat flour1 #ag ,lard1 #fj ,adulterations of1 #fj ,beef stearin1 #fa ,cottonseed oil1 #fj stearin1 #fj ,leach1 caramel in milk1 #a malic acid in vinegar1 #eg salicylic acid in meat1 #aj in milk1 #d ,lemon extract1 #db ,adulterations of1 #db ,citral1 #db ,coloring matter1 #de ,coal-tar dyes1 #de ,turmeric1 #de ,lemon oil1 #db ,methyl alcohol1 #dc ,oil of citronella1 #dc ,tartaric or citric acid1 #dc ,lemon oil in lemon extract1 #db ,lie tea in tea1 #fg ,lythgoe1 coal-tar colors in milk1 #b ,malic acid in vinegar1 #eg ,maple syrup1 #ej ,adulterations of1 #ej ,glucose1 #ej ,marigold in butter1 #f ,marsh1 arsenic in fruit and fruit products1 #ch ,martin1 coloring matter in butter1 #e ,martius yellow in mustard1 #eb ,meats1 #h ,adulterations of1 #h ,canned1 #aa ,coloring matter 7see under sausages1 etc471 #ac ,heavy metals1 #aa ,preservatives 7same tests as under smoked and fresh meat71 #aa ,coloring matter1 #ac ,aniline red and cochineal-carmine in sausage chopped meat preparations1 and corned meat1 #ac ,diseased meat1 #ad ,fresh and smoked1 #h ,preservatives1 #h ,benzoic acid1 #aj ,boric acid1 #i ,potassium nitrate1 #h ,salicylic acid1 #aj ,sulfurous acid1 #i ,fish1 salt1 dried and oysters1 #ac ,preservatives1 #ac ,borax 7same as under fresh meat71 #ac ,boric acid 7same as under fresh meat71 #ac ,horse-flesh in sausage and in mince-meat1 #ad ,starch in sausage1 deviled meat and similar products1 #ac ,metallic impurities in vinegar1 #eh ,methyl alcohol in lemon extract1 #dc ,mineral acids in vinegar1 #ef ,milk1 #a ,adulterations of1 #a ,coloring matter1 #a ,annatto1 #a ,caramel1 #a ,coal-tar dyes1 #b ,gelatin1 #b ,preservatives1 #c ,boric acid1 #d ,formaldehyde1 #c ,salicylic acid1 #d ,starch1 #b ,mohler1 benzoic acid in meat1 #aj in fruit and fruit products1 #cd ,mustard1 #ea ,adulterations of1 #ea ,cayenne pepper1 #ec ,coloring matter1 #ea ,martius yellow or analogous coal-tar dyes1 #eb ,turmeric1 #eb ,flour1 #ea ,oil of citronella in lemon extract1 #dc ,oleomargarine in butter1 #g ,olive oil1 #fa ,adulterations of1 #fa ,cottonseed oil1 #fb ,peanut oil1 #fc ,rape oil1 #fd ,sesame oil1 #fd ,olive stones in pepper1 #ec ,oysters1 preservatives in1 #ac ,peanut oil in olive oil1 #fc ,pepper 7common71 #ec ,adulterations of1 #ec ,cayenne pepper1 #ed ,ground olive stones1 #ec ,peter1 benzoic acid in canned vegetables1 #bh ,pontet1 general test of olive oil1 #fb ,potassium nitrate in meat1 #h ,preservatives3 ,benzoic acid in canned vegetables1 #bg in fruit and fruit products1 #cd in meat1 #aj ,boric acid in fish and oysters1 #ac in meat1 #i in milk1 #d ,formaldehyde in canned vegetables1 #be in milk1 #c ,potassium nitrate in meat1 #h ,saccharin in canned vegetables1 #bf in fruit and fruit products1 #cd ,salicylic acid in canned vegetables1 #bf in fruit and fruit products1 #cd in meat1 #aj in milk1 #d ,sulfites in canned vegetables1 #bf ,sulfurous acid in canned vegetables1 #bf ,process or renovated butter1 #f ,rape oil in olive oil1 #fd ,resins1 foreign1 in vanilla extract1 #df ,richards1 ,mrs41 alum in baking powders1 #bb ,rimmington1 chicory in coffee1 #ff ,saccharin in canned vegetables1 #bf in fruit and fruit products1 #cd ,saffron in butter1 #f ,salicylic acid in canned vegetables1 #bf in fruit and fruit products1 #cd in meat1 #aj in milk1 #d ,schmidt1 saccharin in canned vegetables1 #bg ,schmidt1 ,albert1 chicory in coffee1 #ff ,soaked vegetables1 #cj ,sostegni and ,carpentieri1 coal-tar dyes in canned vegetables1 #bi ,spices in vinegar1 #ei ,stoke1 gelatin in milk1 #b ,substituted flours1 #ag ,corn meal in wheat1 #ag ,general test for1 #ag ,wheat flour in rye1 #ah ,sulfates in baking powders1 #ba ,sulfuric acid in vinegar1 #ef ,sulfurous acid in meat1 #i ,stannous chlorid in ginger cake1 #ai ,starch in fruit and fruit products1 #cg in milk1 #b ,tannin in vanilla extracts1 #dg ,tartar in vinegar1 #ei ,tartaric acid in baking powders1 #bj1 #ba in cream of tartar1 #bb in lemon extract1 #dc in wine vinegar1 #ei ,tea1 #fg ,adulterations of1 #fg ,catechu1 #fh ,exhausted tea leaves1 #fg ,facing1 #fh ,foreign leaves1 #fg ,lie tea1 #fg ,tocher1 sesame oil in olive oil1 #fd ,turmeric in butter1 #f in lemon extract1 #de in mixed pickles1 #cj in mustard1 #eb ,vanilla extract1 #de ,adulterations of1 #de ,alkali1 #df ,caramel1 #dg ,coumarin1 #dh ,foreign resins1 #df ,tannin1 #df ,vanderplanken1 alum in sour bread1 #ai ,vinegar1 #ee ,adulterations of1 #ee ,coloring matter1 #eh ,caramel1 #eh ,coal-tar colors in wine vinegar1 #eh ,glucose1 #ei ,malic acid1 #eg ,metallic impurities1 #eh ,mineral acids 7free71 #ef ,hydrochloric acid1 #eg ,sulfuric acid1 #ef ,spices1 #ei ,tartar in wine vinegar1 #ei ,tartaric acid 7free7 in wine vinegar1 #ei ,vogel1 substituted flours1 #ag ,wynter ,blyth1 alum in flour1 #af ,wolff1 tartaric acid free or combined in baking powders1 #bj ,transcriber's ,notes ,this text follows the source document in spelling and hyphenation1 including inconsistencies1 except as mentioned below4 ,inconsistencies in section heading have been retained as well4 ,the index entries are not always in alphabetical order2 this has not been changed4 ,changes made to the text3 ,some missing or wrong punctuation has been corrected silently4 ,ratios have been changed to x 3 y where relevant4 ,minor typographical errors corrected3 ,page vii3 ,commerical to ,commercial ,page #af3 oelomargarine to oleamargarine ,page #di3 invert suger to invert sugar ,page #fb3 444 7about #c cc4 of this 444 to 444 7about #c cc47 of this 444 ,page #ga3 seasame to sesame ,page #fh3 ,a ,,few ,,of ,,the ,,best ,,books ,,on ,,food ,,analysis has been considered a separate chapter4 ,page #fi3 the page header ,,chemicals has been used as the chapter heading4 ,the following words in the indexes have been changed to conform to those in the text3 ,bechman to ,beckmann2 ,kammerer to ,kmmerer2 ,klingler to ,klinger2 ,winter-,blyth and ,winter ,blyth to ,wynter ,blyth4