,illustration ,,scientific ,,american ,,supplement ,,no4 #ghg ,,new ,,york1 ,january #ca1 #ahia ,scientific ,american ,supplement4 ,vol4 ,,xxxi41 ,no4 #ghg4 ,scientific ,american established #ahde ,scientific ,american ,supplement1 #e a year4 ,scientific ,american and ,supplement1 #g a year4 99 99 99 99 99 ,,table ,,of ,,contents4 ,i4 ,,biography4--,,charles ,,goodyear4--,the life and discoveries of the inventor of vulcanized ,india rubber1 with portrait4--#a illustration ,,ii4 ,,biology4--,can we ,separate ,animals from ,plants8--,by ,,andrew ,,wilson4--,a debated point well discussed4--,the bases on which distinctions must be drawn ,,iii4 ,,electricity4--,a ,new ,electric ,ballistic ,target4--,a target for investigations of the velocity of projectiles1 now in use at the ,united ,states ,military ,academy1 ,west ,point1 ,n4,y4--#a illustration4 ,electric ,erygmascope4--,an electric lighting apparatus for examining earth strata in bore holes for geologists' and prospectors' use4--#a illustration ,the ,electro-,magnet4--,by ,prof4 ,,silvanus ,,thompson4--,continuation of this exhaustive treatise1 giving further details on special points of construction4--#a illustrations ,,iv4 ,,entomology4--,potash ,salts4--,the use of potash salts as insecticides1 with accounts of experiments ,the ,outlook for ,applied ,entomology4--,by ,dr4 ,c4,v4 ,,riley1 ,u4,s4 entomologist4--,the conclusion of ,prof4 ,riley's lecture1 treating of the branch of entomology with which his name is so honorably associated ,v4 ,,insurance4--,the ,expense ,margin in ,life ,insurance4--,elaborate review of the necessary expenses of conducting the insurance of lives1 with tables and calculations ,,vi4 ,,mathematics4--,the ,trisection of ,any ,angle4--,by ,,frederic ,r4 ,,honey1 ,ph4,b4--,a very ingenious demonstration of this problem1 based on the properties of conjugate hyperbolas ,,vii4 ,,meteorology4--,note on the ,mt4 ,blanc ,meteorological ,station ,the ,flood at ,karlsbad4--,account of the recent flood and of its destructive effects4--#a illustration ,,viii4 ,,mechanical ,,engineering4--,station for ,testing ,agricultural ,machines4--,a proposed establishment for applying dynamometer tests to agricultural machines4--#a illustration ,steam ,engine ,valves4--,by ,,thomas ,,hawley4--,a review of modern slide valve practice1 the lap1 cut-off1 and other points4--#f illustrations ,,ix4 ,,miscellaneous4--,science in the ,theater4--,curious examples of stage effect in fictitious mesmerizing and hypnotizing4--#d illustrations ,theatrical ,water ,plays4--,recent episodes in real water plays at ,hengler's ,circus1 ,london4--#b illustrations ,x4 ,,naval ,,engineering4--,the ,french ,ironclad ,war ,ship ,colbert4--,an armored wood and iron ship1 with central battery4--#a illustration ,,xi4 ,,physiology ,,and ,,hygiene4--,newer ,physiology and ,pathology4--,by ,prof4 ,,samuel ,,bell4 ,m4,d4--,an excellent presentation of modern practice in the light of bacteriology ,test ,card ,hints4--,how to test the eyes for selecting eyeglasses and spectacles ,the ,composition of ,koch's ,lymph4--,what ,prof4 ,koch says it is and what it can do4--,the cabled account of the disclosure so long waited for ,,xii4 ,,technology4--,firing ,points of ,various ,explosives4--,the leading explosives1 with the temperature of their exploding points tabulated ,the ,recovery of ,gold and ,silver from ,plating and ,gilding ,solutions--,a paper of interest to silver and gold platers1 as well as photographers ,water ,softening and ,purifying ,apparatus4--,an apparatus for treatment of sewage1 etc41 chemically and by deposition4--#a illustration 99 99 99 99 99 ,,the ,,french ,,ironclad ,,war ,,ship ,,colbert4 ,the central battery ironclad ,colbert is one of the ten ships of the ,french navy that constitute the group ranking next in importance to the squadron of great turret ships1 of which the ,formidable is the largest4 ,the group consists of six types1 as follows3 #a4 ,the ,ocean type2 three vessels2 the ,marengo1 ,ocean1 and ,suffren4 #b4 ,the ,friedland type1 of which no others are built4 #c4 ,the ,richelieu type1 of which no others are built4 #d4 ,the ,colbert type1 of which there are two2 the ,colbert and the ,trident4 #e4 ,the ,redoubtable type1 of which no others are built4 #f4 ,the ,devastation type1 of which no others are built4 ,illustration3 ,,the ,,french ,,ironclad ,,war ,,ship ,,colbert4 ,the ,colbert was launched at ,brest in #ahge1 and her sister ship1 the ,trident1 in #ahgf4 ,both are of iron and wood1 and the following are the principal dimensions of the ,colbert1 which apply very closely to the ,trident3 ,she is #cba ft4 #f in4 long1 #ei ft4 #f in4 beam1 and #bi ft4 #f in4 draught aft4 ,her displacement is #h1deg tons1 her indicated horse power is #d1feb1 and her speed #ad4d knots4 ,she has coal carrying capacity for #gjj tons1 and her crew numbers #gjf4 ,the thickness of her armor belt is #h4ff in41 that protecting the central battery is #f4bi in4 thick1 which is also the thickness of the transverse armored bulkheads1 while the deck is #j4dc in4 in thickness4 ,the armament of the ,colbert consists of eight #aj4fc in4 guns1 two #i4de in41 six #e4ea in41 two quick firing guns1 and fourteen revolving and machine guns4--,engineering4 99 99 99 99 99 ,a compound locomotive1 built by the ,rhode ,island ,locomotive ,works1 has been tried on the ,union ,elevated ,railroad1 ,brooklyn1 ,n4,y4 ,the engine can be run either single or compound4 ,the economy in fuel was #cg4g per cent1 and in water #bc4h per cent1 over a simple engine which was tested at the same time4 ,the smoothness of running and the stillness and comparative absence of cinders was fully demonstrated4 99 99 99 99 99 ,,steam ,,engine ,,valves4 ,footnote3 ,lecture delivered at ,wells ,memorial ,institute1 ,boston1 in the ,lowell ,free ,course for ,engineers4 ,from report in the ,boston ,journal of ,commerce4 ,by ,,thomas ,,hawley4 ,,riding ,,cut-,,off ,,valves--,,peculiarities ,,and ,,merits ,,of ,,the ,,different ,,styles4 ,in considering the slide valve in its simple form with or without lap1 we find there are certain limitations to its use as a valve that would give the best results4 ,the limitation of most importance is that its construction will not allow of the proper cut off to obtain all the benefits of expansion without hindering the perfect action of the valve in other particulars4 ,at this economical cut off the opening of the steam port is very little and very narrow1 and although this is attempted to be overcome by exceedingly wide ports1 sixteen inches in width in many cases in locomotive work1 this great width adds largely to the unbalanced area of the valve4 ,the exhausting functions of the valve are materially changed at the short cut off1 and when much lap is added to overcome this defect1 there usually takes place a choking of the exhaust port4 ,you might inquire1 why not make the port wider1 but this would increase the minimum amount of load on the valve1 and this must not be overlooked4 ,then the cut off is a fixed one1 and we can govern only by throttling the pressure we have raised in the boiler or by using a cut off governor and the consequent wastes of an enormous clearance space4 ,you will observe1 therefore1 that the plain slide valve engine gives the most general satisfaction at about two-thirds cut off and a very low economic result4 ,the best of such engines will require forty-five to fifty pounds of steam per horse power per hour1 and to generate this1 assuming an evaporation of nine pounds of water to a pound of coal1 would require between five and six pounds of coal per horse power per hour4 ,and the only feature that the valve has specially to commend it is its extreme simplicity and the very little mechanism required to operate it4 ,yet this is of considerable importance1 and in consideration of some special features at its latest cut off1 the attempt has been many times made to take advantage of these features4 ,for instance1 at #ij advance1 the valve opens very rapidly indeed and fully satisfies our requirements of a perfect valve4 ,this is one good point1 and in this position also the exhaust and compression can be regulated very closely and as desired without much lap1 and as the opening of the exhaust port comes with the eccentric at its most rapid movement the release is very quick and as we would have it4 ,this is only possible at the most uneconomic position of the valve as regards cut off4 ,the aim of many engineers has been to take advantage of these matters by using the valve with #ij angular advance of eccentric ahead of crank1 for the admission1 release1 and compression of the steam1 and provide another means of cutting off1 besides the one already referred to1 viz41 cutting off the supply of steam to the chest1 and overcome the objection in this one of large clearance spaces4 ,this is done by means of riding cut off valves1 often called expansion valves1 of which1 perhaps1 the most widely known types in this vicinity are the ,kendall ,roberts engine and the ,buckeye4 ,the former is used in the simplest form of riding cut off1 while the ,buckeye has many peculiar features that engineers1 ,i find1 are too prone to overlook in a casual examination of the engine4 ,in these uses of the slide valve1 too1 means are suggested and carried out of practically balancing the valve4 ,the origin of the riding cut off is most generally attributed to ,gonzenbach4 ,his arrangement had two steam chests1 the lower one provided with the ordinary slide valve of late cut off1 and steam was cut off from this steam chest by the expansion valve covering the ports connecting with the upper steam chest4 ,this had the old disadvantage that all the steam in the lower chest expanded with that in the cylinder1 at a consequent considerable loss4 ,this was further improved by causing the riding cut off to be upon the top of the main valve1 instead of its chest1 and resulted in a considerable reduction of the clearance space4 ,this is the simplest form1 and is shown in ,fig4 #a4 ,the steam is supplied by a passage through the main valve which operates exactly as an ordinary slide valve would4 ,that is1 the inside edges of the steam passage are the same as the ordinary valve1 the additional piece on each end1 if ,i may so term it1 being merely to provide a passage for the steam which can be closed1 instead of allowing the steam to pass the edge4 ,the eccentric of the main valve is fastened to the shaft to give the proper amount of lead1 and the desired release and compression1 and the expansion valve is operated by a separate eccentric fastened in line with or #ahj ahead of the crank4 ,when the piston1 therefore1 commences to move from the crank end to open the port1 ,d1 the expansion valve is forced by its eccentric in the opposite direction1 and is closing the steam port and would have closed it before the piston reached quarter stroke1 thus allowing the steam then in the cylinder to do work by expansion4 ,the eccentric operating this expansion valve may be set to close this steam port at any point in the stroke that is desired1 the closing occurring when the expansion valve has covered the steam port4 ,continuing the movements of the valves1 the two would move together until one or the other reached its dead center1 when the movements would be in opposite directions4 ,illustration3 ,,fig4 #a4 ,there are three ways of effecting the cut off in such engines1 the main valve meanwhile being undisturbed1 its eccentric fastened securely so as not to disturb the points of lead1 release1 and compression4 ,all that is required is to cause the edge of the expansion valve to cover the steam port earlier in the stroke1 and this can be done1 first1 by increasing the angular advance of the cut off eccentric2 second1 by adding lap to the cut off valve2 and third by changing the throw of the eccentric4 ,in all these instances the riding valve is caused to reach the edge of the steam port earlier in the stroke4 ,we will take first1 as the simplest1 those methods by which the lap of the cut off valve is increased4 ,it will be noted that there is but one edge of this valve that is required to do any work1 and that is to close the valve4 ,the eccentrics are so placed that the passage in the main valve is opened long before the main valve itself is ready to admit steam to the cylinder1 so that only the outer edges are the ones to be considered1 and it will be readily seen that the two valves traveling in opposite directions1 any lap added to the working edge of the cut off valve will cause it to reach the edge and therefore close the port earlier than it would if there was less lap4 ,and we might carry it to the extreme that we could add lap enough that the steam passage would not be opened at all4 ,in ,fig4 #b is shown the method by which this is accomplished1 in what is called ,meyer's valve1 and such as is used in the ,kendall ,roberts engine4 ,we have only one point to look after1 the cut off1 so we can add all the lap we wish without disturbing anything else4 ,in this engine the lap is changed by hand by means of a little hand wheel on a stem that extends out of the rear of the steam chest4 ,the valve is in two sections1 and when it is desired to cut off earlier1 the hand wheel is turned in such a direction that the right and left hand screws controlling the cut off valve move one valve portion back and the other forward1 which would1 if they were one valve and they should be so considered1 have the effect of lengthening them1 or adding lap to them4 ,the result would be that the riding valve would reach the edge of the steam port earlier in the stroke1 bringing about an earlier cut off4 ,if the cut off is desired to be later1 the hand wheel is so turned that the right and left hand screws will bring the valve sections nearer together1 thus practically taking off lap4 ,now this may be done by hand or it may be done by the action of a governor4 ,illustration3 ,,fig4 #b4 ,in the latter case the governor at each change of load turns the right and left hand screws to add or take away lap1 as the load demands an earlier or later cut off2 in other cases the governor moves a rack in mesh with a gear by which the valve sections are brought closer together or are separated4 ,the difficulty with the case where the hand wheel is turned by hand is that the cut off is fixed where you leave it1 and governing can only be at the throttle4 ,for this reason anywhere near full boiler pressure would not be obtained in the cylinder of the engine4 ,if the load was a constant one1 and the cut off could be fixed at about one-third1 causing the throttle to open its widest1 very good results would be obtained1 but there is no margin left for governing4 ,if the load should increase at such a time the governor could not control it under these conditions1 and it would lead to a decrease in speed unless the lap was again changed to give a later cut off4 ,on this account the general practice soon becomes to leave the cut off at the later point and give range to the throttle1 and we come back once more to the plain slide valve cutting off at half stroke1 and the only gain there is1 is in a quick port opening and quick cut off4 ,but these matters are more than offset by the wire drawing between the steam pipe and chest1 through the throttle1 and the fact that there is added to the friction of the engine the friction of this additional slide valve and a considerable liability to have a leaky valve4 ,in the case where the governor changes the position of the cut off valve a greater decree of economy would result4 ,in this engine1 of which the ,lambertville engine is a type1 the main valve is a long ,d slide1 with multiple ports at the ends through which the steam enters the cylinders4 ,it is operated from an eccentric on the crank shaft in the usual manner4 ,the cut off valve is also operated from the motion on an eccentric fixed upon the crank shaft4 ,the rod or stem of the cut off valve passes through the main valve rod and slide4 ,upon the outer end of the cut off valve rod are tappets fastened to engage with tappets on the eccentric valve rod4 ,connection between the cut off eccentric1 therefore1 and the cut off valve is only by means of the engagement of these tappets4 ,the eccentric rod is fastened to a rocker arm having motion swinging about a pin or bearing in the governor slide1 which may be raised or lowered by a cam operated by the governor4 ,the cut off slide is of cylindrical shape and incloses a spring and dash pot with disks attached by means of which the valve is closed4 ,the motion for operating the valves is relatively in the same direction1 the cut off eccentric having the greatest throw and greater angular advance to cause it to open earlier and quickly before the main valve is ready to admit steam4 ,the cut off eccentric rod swinging the rocker arm1 the tappets thereon engage with those upon the cut off valve rod and open the passages to the main valve1 and in their movement compress the spring in the main valve4 ,according as the speed of the engine1 the rock arm will be raised or lowered so that the tappets upon the eccentric rod may keep in engagement a shorter or longer time before they disengage1 thus allowing the spring that has been compressed by the movement of the cut off valve to close that valve quickly and the supply of steam to the engine1 the cut off valve traveling with the main valve for the balance of the stroke4 ,this device will give a remarkably quick opening and a quick cut off1 but in view of the fact that the governor has so much to do1 its delicacy is impaired and a quick response to the demands of the load changing not so likely to occur4 ,the cut off cannot be as quick as in some other engines1 because the valves are moving in opposite directions1 and while this fact would help1 so far as shortening the distance to be traveled before cut off1 the resistance of the valves to travel in opposite directions1 or rather the tendency of the valve to travel with the main valve1 hinders its rapid action4 ,illustration3 ,,fig4 #c4 ,this is one great objection to the rack and gear operated by the governor1 that two flat valves riding upon each other and sliding in opposite directions at times require a considerable amount of force to move them1 and as only a slight change in load is required by the load1 the governor cannot handle the work as delicately as it should4 ,it is too much for the governor to do well4 ,to overcome this difficulty the ,ryder cut-off1 shown in ,fig4 #c1 was made by the ,delamater people1 of ,new ,york4 ,the main slide valve is hollowed in the back and the ports cut diagonally across the valve to form almost a letter ,v4 ,the expansion valve is ,v-shaped1 and circular to fit its circular-seat4 ,the valve rod of the expansion valve has a sector upon it and operated by a gear upon the governor stem1 which rotates the valve rod1 and the edge of the valve rod is brought farther over the steam port1 thus practically adding lap to the valve4 ,little movement is found necessary to make the ordinary change in cut-off1 and it is found to be much easier to move the riding valve across the valve than in a direction directly opposite4 ,it would require considerable force to move the upper valve by the governor faster than the lower1 or in a direction opposite to that in which it is moving1 but very little force applied sideways at the same time it is moving forward will give it a sideways motion4 ,in this device the governor has only to exert this side pressure and therefore has less to do than if it were called upon to move the upper valve directly against the movement of the lower4 ,something similar is the valve of the ,woodbury engine1 of ,rochester1 ,n4,y4 ,the cut-off valve is cylindrical1 covering diagonal ports directly opposite1 and is caused to be rotated by the action of the governor that operates a rack in mesh with a segment4 ,very little movement will effect a considerable change in the lappage of the valve1 the valve turning about one-quarter a revolution for the extremes of cut off4 ,the cut off valve rod works through a bracket and its end terminates in a ball in a socket on the end of the eccentric rod4 ,in this case the governor has not as much to do as in other instances4 ,illustration3 ,,fig4 #d4 ,still another method of effecting this change in cut off1 but hardly by increasing the lap of the valve1 is shown in the next drawing1 ,fig4 #d4 ,the cut off valve is held upon the main valve by the pressure of steam upon its back and rides with it until it comes in contact with the cut off wedge-shaped blocks1 when its motion is arrested1 and the main valve continuing its movement the steam port is closed by the main valve passing beneath the cut off valve4 ,thus the main valve travels and carries the cut off valve upon its back again until the cut off valve strikes the wedge on the other end and the cut off is effected4 ,the relative positions of the blocks are determined by the governor1 that will raise or lower them so that the cut off valve will engage with them earlier or later as desired4 ,this device was designed specially as an inexpensive method of changing the common slide valve into an automatic cut off4 ,the cut off would not be as quick as in other cases we have cited1 depending here upon the movement of the lower valve alone1 and that1 too1 is in its slowest movement2 whereas in the other cases1 the edges approaching each other1 by the differing movement of the valves the cut off is very rapid1 provided the distance to travel is not long4 ,in this device considerable noise must result by the cut off valve striking the cut off blocks1 and a considerable amount of leakage is likely to occur past this valve4 ,but there is one great objection in the valve gears thus far cited1 that the travel of the expansion valve upon the main valve is variable4 ,i have in mind the case of a ,kendall ,roberts engine1 which had been run for a long time at no better economy than would be obtained from a plain slide valve engine1 and when it was attempted to get an earlier cut off by separating the two cut off valves1 they had worn so much in their old place on the valve that shoulders were found sufficient to cause a disagreeable noise and a leaky valve4 ,this is very apt to occur1 not only where the valve is run for a long time on one seat1 but in cases of variation of the travel of the expansion valve4 ,the result is that a change will bring about a leaky valve1 something that every engineer abhors4 ,the construction of the ,buckeye engine1 which is also of this type1 is such that the travel of the valve on the back of the main valve is always the same1 no matter what the cut off may be4 ,then this engine makes use of our second proposition as a means of effecting the cut off1 viz41 by advancing the eccentric4 ,you will readily observe that anything that will cause the cut off valve to reach a certain point earlier in the stroke will bring about an earlier cut off as it hastens everything all around4 ,this is the plan pursued in the ,buckeye1 in which the governor1 of the shaft type1 turns the eccentric forward or back according as the load demands4 ,then1 in addition1 the valve is balanced partially1 the attempt not being made to produce an absolutely balanced valve1 on the ground that there should be friction enough to keep the surfaces bright and to prevent leakage4 ,the most perfect valve will1 of course1 be entirely balanced under all conditions of pressure so as to move with perfect ease4 ,with the riding cut off valve in connection with the plain slide valve1 this is not accomplished1 and it does not matter whether it is partially unbalanced to prevent leakage or not1 the fact that it is not entirely balanced prevents it reaching the ideal valve4 ,illustration3 ,fig4 #e ,this valve1 ,fig4 #e1 differs from the others also in this particular1 that the exhaust takes place at the end of the valve instead of under the arch4 ,two eccentrics are used1 the one for the main valve being fastened to the shaft and the other riding loosely upon it and connected to the fly wheel governor1 by which it may be turned forward or back as the load requires4 ,the three points of lead1 or admission and exhaust and compression1 are fixed and independent of the changes and cut off4 ,the motion of the main eccentric is given to a rocker arm1 the pivot of which is at the bottom1 and from the upper end the valve rod transfers the motion to the valve without reversing the motion1 as is done sometimes in the slide valve to overcome the effects of the angularity of the connecting rod4 ,the action of the rocker arm1 therefore1 so far as the main valve in the ,buckeye is concerned1 is no different than that which would occur if no rocker arm intervened4 ,the motion of the cut off eccentric1 through its eccentric rod1 is given to a rocker rocking in a bearing in the center of the main rocker arm 7see ,fig4 #f74 ,the motion of this eccentric is reversed1 so far as the cut off valve is concerned1 and when the cut off eccentric is moving forward1 the cut off valve is being pushed back4 ,the main valve rod is hollow1 and the cut off valve rod passes through it4 ,illustration3 ,fig4 #f ,the cut off eccentric can be placed in any position to cause it to cut off as desired1 and by drawing the valve forward1 by increasing the angular advance of the eccentric1 the cut off valve is caused to reach and cover the steam passage in the main valve earlier in the stroke4 ,instead of being ahead of the crank1 the main eccentric in this arrangement follows the crank1 on account of the exhaust and steam edges being exactly opposite from those in the ordinary slide4 ,what is the steam edge of the common slide is in this the exhaust edge1 and what is the exhaust edge in the common valve is the steam edge in this one4 ,the valve1 therefore1 must be moved in the opposite direction from what is ordinarily the case1 the main eccentric being not #ij deg4 behind the crank4 ,it has a rapid and full opening just the same1 for it is at this point behind the crank1 or ahead of it1 that the eccentric gives to the valve its quickest movement1 or between the eccentric dead centers4 ,the cut off eccentric is considerably ahead of the main eccentric1 and about even with the crank4 ,if it was not for the reversal of motion of the cut off valve through the rocker arm this eccentric would be about in line with the crank1 but on the other end4 ,the movement of the cut off valve1 therefore1 at the time of port opening is very little1 being about on its dead center1 passing which1 it immediately commences to close4 ,the object of the peculiar construction of the rocker arm1 and the pivot for the cut off rocker being placed thereon1 is to provide equal travel on the back of the main valve1 no matter what the cut off4 ,i have already explained1 in connection with the slide valve1 that advancing the eccentric does not change the movement of the valve on its seat1 but simply its relation to the movement of the piston4 ,you will see that this is unchanged as using the main valve as a seat or any other seat4 ,if the main valve was to remain stationary1 and only the cut off valve to be operated by its eccentric1 the movement of this cut off valve on a certain plane would be the same for all positions of the eccentric4 ,moving the main slide does not affect the matter in any way1 for it moves at the same time the pivot of the cut off1 and while the cut off seat has assumed a different position with reference to the engine1 it is still as though stationary so far as the cut off valve is concerned4 ,this is the object of this peculiar construction1 and not1 as some engineers suppose1 simply to make an odd way of doing things4 ,and the object of it all is to give at all cut offs the same amount of travel1 so that there might be no unequal wear to bring about a leak1 to prevent which a perfect balancing has been sacrificed4 ,referring to the valve and this engine as to how it will satisfy our requirements of a perfect valve gear1 we find that the first requirement of a rapid and full opening is met1 in that the opening occurs when the main eccentric is moving very rapidly1 yet not its fastest1 and while this opening will be very satisfactory1 it is not so rapid an opening as is obtained in some other forms of valves and valve gears1 but this could be overcome very readily by increasing the lead a trifle1 and in my experience with these engines ,i find that the practice is very general by engineers and by builders themselves to give them a considerable amount of lead4 ,as to the second requirement1 the maintenance of initial pressure until cut off1 giving a straight steam line1 cards from this engine will not be found to show that the engine satisfies this requirement1 and for this reason1 that the cut-off valve commences to close the port immediately after the piston commences to move4 ,the cut off eccentric you will remember is set to move with the crank or very nearly so1 and the lighter the load1 the greater will this fact appear4 ,for the lightest loads the governor places the eccentric in advance of the crank1 so that the cut off valve will commence to close the port before steam is admitted by the main valve to the engine4 ,now1 the later the cut off1 the less will this wire drawing appear at first1 and the shorter the cut off1 the amount of wire drawing increases sensibly4 ,the operation of the valve1 therefore1 in this particular1 cannot be considered as meeting our requirement that the port shall be held open full width until ready to be closed4 ,many men claim for this engine that the closing occurs when the cut off eccentric is moving its fastest4 ,this is a fact1 and if we consider the point of cut off only to be the point of absolute cut off1 the cut off must be instantaneous1 for there is an instantaneous point where the cut off is final only to be considered4 ,the reasoning applied here would hold good also to a less extent on the slide valve1 but is not the point of absolute cut off4 ,we want to note how long it is from the time the valve commences to close at all until finally closed1 and1 as ,i have shown you1 this is considerable in this engine4 ,referring to the point of cut off finally1 it is determined upon by a governor of the fly wheel type4 ,the eccentric is loose about the shaft1 and arms projecting therefrom are connected by other arms to the extremity of an arm upon which is mounted a weight1 and which is attached to the spokes of the fly wheel1 or special governor wheel in this case1 and which is fastened to the crank shaft4 ,as the speed increases through throwing off a portion of the load the governor weights fly out1 and this movement is transferred through the lever connections to the eccentric1 causing it to be turned ahead1 and the manner hastening the movement of the cut off valve on its seat and causing it to reach and cover the edge of the steam port earlier in the stroke4 ,this engine was the pioneer in governors of this character1 the advantage being1 in addition to its necessity for the work of turning the eccentric ahead or back1 that the liability of the engine to run away1 as very often happens from the breaking of the governor belt or a similar cause1 was not possible4 ,the cut off valve has a travel considerably beyond the edge of the steam passage after the valve is closed1 and this has one advantage1 that the valve is less liable to leak1 and to this must be added the loss from the friction of this moving valve1 and moving too in opposition to the main valve4 ,in our perfect valve1 as we outlined it1 the valve does not move after the port is closed4 ,the exhausting functions of the valve are very good1 giving a quick opening and a full opening1 because this opening occurs when the eccentric is moving its fastest4 ,the engine also possesses a distinct advantage in having remarkably small clearance spaces4 ,the length of the steam passage is very small in comparison with any form of engine1 and having but two ports instead of four1 as in the ,corliss and four valve type4 ,in these there must be included in the clearance1 that to the exhaust port as well as the steam port1 adding a considerable amount where the piston comes close to the head4 ,as the engines leave the maker's hand the engines are provided with a considerable amount of lap to give plenty of compression1 but are1 of course1 capable of having more added to increase compression1 or some planed off to decrease it4 ,one of the peculiar things about this engine is the failure to realize anywhere near boiler pressure1 noticeable in every case that has come under my notice4 ,the considerable lead gives it for an instant1 but it soon falls away1 indicating the steam chest pressure only by a peak at the junction of the admission and steam lines4 ,this is probably due to the fact that the cut off valve commences closing the steam passage so soon after steam is admitted1 and in this particular does not satisfy the requirements of a perfect valve4 ,there is this about the engine1 that above all others of this type there has come under my notice fewer engines of this type with a maladjustment of valves from tampering by incompetent engineers4 99 99 99 99 99 ,,firing ,,points ,,of ,,various ,,explosives4 ,an apparatus1 devised by ,horsley1 was used1 which consisted of an iron stand with a ring support holding a hemispherical iron vessel1 in which paraffin or tin was put4 ,above this was another movable support1 from which a thermometer was suspended and so adjusted that its bulb was immersed in molten material in the iron vessel4 ,a thin copper cartridge case1 #e_/h in4 in diameter and #a-e_/af in4 long1 was suspended over the bath by means of a triangle1 so that the end of the case was #a in4 below the surface of the liquid4 ,on beginning the experiment the material in the bath was heated to just above the melting point1 the thermometer was inserted in it1 and a minute quantity of the explosive was placed in the bottom of the cartridge case4 ,the temperature marked by the thermometer was noted as the initial temperature1 the cartridge case containing the explosive was inserted in the bath1 and the temperature quickly raised until the explosive flashed off or exploded1 when the temperature marked by the thermometer was again noted as the firing point4 ,the tables given show the results of about six experiments with each explosive4 ,the initial temperatures range from #fe to #bhj ,c4 in some cases1 but as the firing points remained fairly constant1 only the extremes of the latter are quoted in the following table3 ---------------------------------------- --------------- ,description of ,explosive4 ,firing ,point in ,c4 ---------------------------------------- --------------- ,compressed military gun-cotton4 #ahf - #bja ,air-dried military gun-cotton4 #agi - #ahf #ahf - #ahi #acg - #aci #aed - #afa ,gun-cotton dried at #fe ,c4 #acf - #ada ,air-dried collodion gun-cotton4 #ahf - #aia #aig - #aii #aic - #aie ,air-dried gun-cotton4 #aib - #aig #aid - #aii ,hydro-nitrocellulose4 #bja - #bac ,nitroglycerin4 #bjc - #bje ,kieselghur dynamite4 ,no4 #a4 #aig - #bjj ,explosive gelatin4 #bjc - #bji ,explosive gelatin1 camphorated4 #agd - #ahb ,mercury fulminate4 #age - #aha ,gunpowder4 #bgh - #bhg ,hill's picric powder4 #bgc - #bhc #bgc - #bij ,forcite1 ,no4 #a4 #ahd - #bjj ,atlas powder1 #ge per cent4 #age - #ahe ,emmensite1 ,no4 #a4 #afg - #ahd ,emmensite1 ,no4 #b4 #afe - #agg ,emmensite1 ,no4 #e4 #bje - #bag ---------------------------------------- --------------- --,c4,e4 ,munroe1 ,j4 ,amer4 ,chem4 ,soc4 99 99 99 99 99 ,,station ,,for ,,testing ,,agricultural ,,machines4 ,the minister of agriculture has recently established a special laboratory for testing agricultural materiel4 ,this establishment1 which is as yet but little known1 is destined to render the greatest services to manufacturers and cultivators4 ,in fact1 agriculture now has recourse to physics and mechanics as well as to chemistry4 ,now1 although there were agricultural laboratories whose mission it was to fix the choice of the cultivator upon such or such a seed or fertilizer1 there was no official establishment designed to inform him as to the value of machines1 the models of which are often very numerous4 ,chemical advice was to be had1 but mechanical advice was wanting4 ,it is such a want that has just been supplied4 ,upon the report presented by ,mr4 ,tisserand1 director of agriculture1 a ministerial decree of the #bdth of ,january1 #ahhh1 ordered the establishment of an experimental station4 ,mr4 ,ringelmann1 professor of rural engineering at the school of ,grignon1 was put in charge of the installation of it1 and was appointed its director4 ,he immediately began to look around for a site1 and on the #agth of ,december1 #ahhh1 the ,municipal ,council of ,paris1 taking into consideration the value of such an establishment to the city's industries1 decided that a plot of ground of an area of #c1cji square meters1 situated on ,jenner ,street1 should be put at the disposal of the minister of agriculture for fifteen years for the establishment thereon of a trial station4 ,this land1 bordering on a very wide street and easy of access1 opposite the municipal buildings1 offers1 through its area1 its situation1 and its neigborhood1 indisputable advantages4 ,a fence #gj meters in extent surrounds the station4 ,an iron gate opens upon a paved path that ends at the station4 ,the year #ahhi was devoted to the installation1 and the station is now in full operation4 ,the tests that can be made here are many1 and concern all kinds of apparatus1 even those connected with the electric lighting that the agriculturist may employ to facilitate his exploitation4 ,however1 the tests that are oftenest made are 7#a7 of rotary apparatus1 such as mills1 thrashing machines1 etc42 7#b7 of traction machines1 such as wagons1 carts1 plows1 etc42 and 7#c7 of lifting apparatus4 ,it is possible1 also1 to make experiments on the resistance of materials4 ,the experimental hall contains a #g horse power gas motor1 dynamometers with automatic registering apparatus1 counters1 balances1 etc4 ,a small machine shop contains a lathe1 a forge1 a drilling machine1 etc4 ,the main shaft is #ab meters in length and is #g centimeters in diameter4 ,it is supported at a distance of one meter from the floor by four pillow blocks1 and is formed of three sections united by movable coupling boxes4 ,out of these #ab meters1 #i are in the hall and #c extend beyond the hall to an annex1 #ad meters in length and #d in width1 in which tests are made of machines whose operation creates dust4 ,when the machines to be tested require more than the power of seven horses that the motor gives1 the persons interested furnish a movable engine1 which1 placed under the annex1 actuates the driving shaft4 ,alongside of the main building there is a ring for experimenting upon machines actuated by a horse whim4 ,there will soon be erected in the center of the grounds an #ah meter tower for experiments on pumps4 ,platforms spaced #e meters apart1 a crane at the top1 and some gauging apparatus will complete this hydraulic installation4 ,the equipment of the hall is very complete1 and is fitted for all kinds of experiments4 ,illustration3 ,,station ,,for ,,testing ,,agricultural ,,machines--,,dynamometer ,,for ,,testing ,,rotary ,,machines4 ,the tests of rotary machines are made by means of a dynamometer 7see figure74 ,two fast pulleys and one loose pulley are interposed between the machine to be tested and the motor4 ,the pulley connected with the motor carries along the one connected with the machine1 through the intermedium of spring plates1 whose strength varies with the nature of the apparatus to be tested4 ,the greater or less elongation of these plates gives the tangential stress exerted by the driving pulley to carry along the pulley that actuates the machine to be tested4 ,this elongation is registered by means of a pencil connected with the spring plates1 and which draws a diagram upon a sheet of paper4 ,at the same time1 a special totalizer gives the stress in kilogrammeters4 ,besides1 the pulley shaft actuates a revolution counter1 and a clock measures the time employed in the experiment4 ,in order to obtain a simultaneous starting and stopping point for all these apparatus1 they are connected electrically1 and1 through the maneuver of a commutator1 are all controlled at once4 ,the electric current is furnished by two series of bichromate batteries4 ,the tests of traction machines are effected by means of a three-wheeled vehicle carrying a dynamometer4 ,the front wheel is capable of turning freely in the horizontal plane1 and the dynamometer is mounted upon a frame provided with a screw that permits of regulating its position according to the slope of the ground4 ,the method of suspension of the dynamometer allows it to take automatically the inclination of the line of traction without any torsion of the plates4 ,there are two models of this vehicle1 one designed to be drawn by a man1 and the other by a horse4 ,the station is provided1 in addition1 with registering pressure gauges1 a large double dynamometric indicator1 a counter of electricity1 balances of precision1 etc4 ,an apparatus designed for measuring the rendering of presses is now in course of construction4 ,although the station has been in operation only from the #ast of ,january1 twenty-five machines have already been presented to be tested4--,extract from ,le ,genie ,civil4 99 99 99 99 99 ,,water ,,softening ,,and ,,purifying ,,apparatus4 ,we have recently had brought under our notice a system of water and sewage purification which appears to possess several substantial advantages4 ,chief among these are simplicity in construction and operation1 economy in first cost and working and efficiency in action4 ,this system is the invention of ,messrs4 ,slack ,brownlow1 of ,canning ,works1 ,upper ,medlock ,street1 ,manchester1 and the apparatus adopted in carrying it out is here illustrated4 ,it consists of an iron cylindrical tank having inside a series of plates arranged in a spiral direction around a fixed center1 and sloping downward at a considerable angle outward4 ,the water to be purified and softened flows through the large inlet tube to the bottom1 mixing on its way with the necessary chemicals1 and entering the apparatus at the bottom1 rises to the top1 passing spirally round the whole circumference1 and depositing on the plates all solids and impurities4 ,all that is needed in the way of attention1 even when dealing with sewage1 or the most polluted waters1 is stated to be the mixing in the small tanks the necessary chemical reagents1 at the commencement of the working day2 and at the close of the day the opening of the mud cocks shown in our engraving1 to remove the collected deposit upon the plates4 ,for the past six months this system has been in operation at a dye works in ,manchester1 successfully purifying and softening the foul waters of the river ,medlock4 ,it is stated that #hd1jjj gallons per day can be easily purified by an apparatus #g feet in diameter4 ,the chemicals used are chiefly lime1 soda1 and alumina1 and the cost of treatment is stated to vary from a farthing to twopence per #a1jjj gallons1 according to the degree of impurity of the water or sewage treated4 ,the results of working at ,manchester show that all the visible filth is removed from the ,medlock's inky waters1 besides which the hardness of the water is reduced to about #f from a normal condition of about #cj4 ,the effluent is fit for all the varied uses of a dye works1 and is stated to be perfectly capable of sustaining fish life4 ,with results such as these the system should have a promising future before it in respect of sewage treatment1 as well as the purification and softening of water generally for industrial and manufacturing purposes4--,iron4 ,illustration3 ,,water ,,softening ,,and ,,purifying ,,apparatus4 99 99 99 99 99 ,,the ,,trisection ,,of ,,any ,,angle4 ,by ,,frederic ,r4 ,,honey1 ,ph4,b41 ,yale ,university4 ,the following analysis shows that with the aid of an hyperbola any arc1 and therefore any angle1 may be trisected4 ,if the reader should not care to follow the analytical work1 the construction is described in the last paragraph--referring to ,fig4 ,,ii4 ,let a b c d 7,fig4 ,i47 be the arc subtending a given angle4 ,draw the chord a d and bisect it at o4 ,through o draw e f perpendicular to a d4 ,we wish to find the locus of a point c whose distance from a given straight line e f is one-half the distance from a given point d4 ,in order to write the equation of this curve1 refer it to the co-ordinate axes a d 7axis of ,x7 and e f 7axis of ,y71 intersecting at the origin o4 ,let g c x ,therefore1 from the definition c d #bx ,let o d ,d ,hence h d ,d-x ,let c h y ,hence 7#bx7 y 7,d-x7 or #dx y ,d-#b;,dx x ,hence y-#cx ,d-#b;,dx o ,i4 ,this is the equation of an hyperbola whose center is on the axis of abscisses4 ,in order to determine the position of the center1 eliminate the x term1 and find the distance from the origin o to a new origin o'4 ,let ,e distance from o to o' ,hence x x' ,e ,substituting this value of x in equation ,i4 y-#c7x' ,e7 ,d-#b;,d7x' ,e7 o or y-#cx-#f;,ex'-#c;,e ,d-#b;,dx'-#b;,,de o ,,ii4 ,in this equation the x' terms should disappear4 ,hence -#f;,ex' - #b;,dx' o ,hence -,e - ,d_/#c ,that is1 the distance from the origin o to the new origin or the center of the hyperbola o' is equal to one-third of the distance from o to d2 and the minus sign indicates that the measurement should be laid off to the left of the origin o4 ,substituting this value of ,e in equation ,,ii41 and omitting accents-- ,we have y - #cx #b;,dx - ,d_/#c ,d - #b;,dx #b;,d_/#c o ,hence y - #cx - #d;,d_/#c ,illustration3 ,fig ,i ,illustration3 ,fig ,,ii ,this is the equation of an hyperbola referred to its center o' as the origin of co-ordinates4 ,to write it in the ordinary form1 that is in terms of the transverse and conjugate axes1 multiply each term by ,c1 i4e41 ,let _/,c semi-transverse axis4 ,,tex3 sqrt,c textsemi-transverse axis4 ,thus ,cy - #c;,cx - #d;,,cd_/#c4 ,,iii4 ,when in this form the product of the coefficients of the x and y terms should be equal to the remaining term4 ,that is #c;,c - #d;,,cd_/#c4 ,hence ,c #d;,d_/#i4 ,and equation ,,iii4 becomes3 #d;,d #d;,d #af;,d#d ----- y - ----- x - --------- #i #c #bg ,,tex3 frac#d;,d#bi y#b - frac#d;,d#bc x#b -frac#af;,d#dbg _/ #d;,d #b;,d ,the semi-transverse axis _/ ----- ---- #i #c ,,tex3 text,the semi-transverse axis sqrtfrac#d;,d#bi frac#b;,d#c _/ #d;,d #b;,d ,the semi-conjugate axis _/ ----- ----- #c _/ #c ,,tex3 text,the semi-conjugate axis sqrtfrac#d;,d#bc frac#b;,dsqrt#c ,since the distance from the center of the curve to either focus is equal to the square root of the sum of the squares of the semi-axes1 the distance from o' to either focus _/#d;,d #d;,d #d;,d _/ _/----- ----- ---- _/ #i #c #c ,,tex3 sqrtfrac#d;,d#bi frac#d;,d#bc frac#d;,d#c ,we can therefore make the following construction 7,fig4 ,,ii47 ,draw a d the chord of the arc a c d4 ,trisect a d at o' and k4 ,produce d a to l1 making a l a o' o' k k d4 ,with a k as a transverse axis1 and l and d as foci1 construct the branch of the hyperbola k c c' c1 which will intersect all arcs having the common chord a d at c1 c'1 c1 etc41 making the arcs c d1 c' d1 c d1 etc41 respectively1 equal to one-third of the arcs a c d1 a c' d1 a c d1 etc4 99 99 99 99 99 ,,test ,,card ,,hints4 ,by ,dr4 ,f4 ,,ogden ,,stout4 ,i know it is the custom with a great many if not the majority of opticians to fit a customer without knowing whether he has presbyopia1 hypermetropia1 or any of the other errors of refraction4 ,their method is first to try a convex1 and if this does not improve1 a concave1 etc41 until the proper one is found4 ,this1 of course1 amounts to the same thing if the right glass is found4 ,but in practice it will be found both time saving and more satisfactory to first decide with what error you have to deal4 ,it is very simple1 and1 where you have no other means of diagnosing 7such as the ophthalmoscope71 it does away with the necessity of trying so many lenses before the proper one is found4 ,you should have a distance test card placed at a distance of twenty feet from the person you are examining1 and in a good light4 ,a distance test card consists of letters of various sizes which it has been found can be seen at certain distances by people with good vision4 ,thus the largest letter is marked with a cc1 meaning that this should be seen at two hundred feet1 and another line1 ,,xx1 at twenty feet1 which is the proper distance for testing vision for distance1 for the reason that a normal eye is at rest when looking at any object twenty feet from it or beyond1 and the rays coming from it are parallel and come to a focus on the retina4 ,you must also have a near vision test card with lines that should be seen by a normal eye from ten to seventy-two inches1 and a card of radiating lines for astigmatism4 ,with this preparation you are ready to proceed4 ,to illustrate1 the first customer comes and tells you that up to six months ago he had very good vision1 but he finds now that1 especially at night1 he has trouble in reading or writing1 and that he finds he can see better a little farther away4 ,his head aches and eyes smart4 ,you will of course say that this is a very simple case4 ,it must be old sight 7presbyopia74 ,probably it is if he is old enough 7#de71 but you must prove this for yourself1 without asking his age1 which is embarrassing in the case of a lady4 ,if you direct him to the distance card twenty feet away1 and find that he can see every one down to and including the one marked ,,xx1 his vision is up to the standard for distance1 and you know that he can have no astigmatism worth correcting1 nor any near sight1 as both of these affect vision for distance1 but he may have far sight or old sight or both combined4 ,you must find which it is4 ,if1 while he is still looking at the twenty-foot line1 you place in front of the eyes a weak convex and he tells you he sees just as well with as without1 it proves the existence of far-sight or hypermetropia1 and the strongest convex that still leaves vision as good for distance as without any1 corrects the manifest4 ,but if the weak convex blurs it1 it shows that there is some defect in focusing1 if the near vision is below normal4 ,you therefore know that you have a case of old sight or presbyopia1 requiring the weakest convex to correct it1 that will enable your customer to see the finest line on the near card at the required distance4 ,the next customer that comes to be fitted with glasses can only see the line marked ,,xl on the distance card at #bj feet or about one-half of what he should see1 which leads you to think that there is no far sight1 for vision for distance is good except in very high degrees of this error4 ,nor can there be old-sight1 for vision for distance is good in old-sight until after the fifty-fifth year1 but it can be near sight 7myopia7 or astigmatism1 or both4 ,we next try the near card and find that even the finest line can be seen clearly if held sufficiently close to the eyes4 ,we now know that this is a case of near sight1 and we must fit them with glasses for distance4 ,the weakest concave that will enable him to see the line that should be seen on the distance card at #bj feet is the proper one to give him for use4--,the ,optician4 99 99 99 99 99 ,,charles ,,goodyear4 ,,charles ,,goodyear was born in ,new ,haven1 ,december #bi1 #ahjj4 ,he was the son of ,amasa ,goodyear1 and the eldest among six children4 ,his father was quite proud of being a descendant of ,stephen ,goodyear1 one of the founders of the colony of ,new ,haven in #afch4 ,amasa ,goodyear owned a little farm on the neck of land in ,new ,haven which is now known as ,oyster ,point1 and it was here that ,charles spent the earliest years of his life4 ,when1 however1 he was quite young1 his father secured an interest in a patent for the manufacture of ivory buttons1 and looking for a convenient location for a small mill1 settled at ,naugatuck1 ,conn41 where he made use of the valuable water power that is there4 ,aside from his manufacturing1 the elder ,goodyear ran a farm1 and between the two lines of industry kept young ,charles pretty busy4 ,in #ahaf1 ,charles left his home and went to ,philadelphia to learn the hardware business4 ,he worked at this very industriously until he was twenty-one years old1 and then1 returning to ,connecticut1 entered into partnership with his father at the old stand in ,naugatuck1 where they manufactured not only ivory and metal buttons1 but a variety of agricultural implements1 which were just beginning to be appreciated by the farmers4 ,in ,august of #ahbd he was united in marriage with ,clarissa ,beecher1 a woman of remarkable strength of character and kindness of disposition1 and one who in after years was of the greatest assistance to the impulsive inventor4 ,two years later he removed again to ,philadelphia1 and there opened a hardware store4 ,his specialties were the valuable agricultural implements that his firm had been manufacturing1 and after the first distrust of home made goods had worn away--for all agricultural implements were imported from ,england at that time--he found himself established at the head of a successful business4 ,this continued to increase until it seemed but a question of a few years until he would be a very wealthy man4 ,between #ahbi and #ahcj he suddenly broke down in health1 being troubled with dyspepsia4 ,at the same time came the failure of a number of business houses that seriously embarrassed his firm4 ,they struggled on1 however1 for some time1 but were finally obliged to fail4 ,the ten years that followed this were full of the bitterest struggles and trials to ,goodyear4 ,under the law that then existed he was imprisoned time after time for debts1 even while he was trying to perfect inventions that should pay off his indebtedness4 ,between the years #ahca and #ahcb he began to hear about gum elastic and very carefully examined every article that appeared in the newspapers relative to this new material4 ,the ,roxbury ,rubber ,company1 of ,boston1 had been for some time experimenting with the gum1 and believing that they had found means for manufacturing goods from it1 had a large plant and were sending their goods all over the country4 ,it was some of their goods that first attracted his attention4 ,soon after this ,goodyear visited ,new ,york1 and went at once to the store of the ,roxbury ,rubber ,company4 ,while there1 he examined with considerable care some of their life preservers1 and it struck him that the tube used for inflation was not very perfect4 ,he1 therefore1 on his return to ,philadelphia1 made some tubes and brought them down to ,new ,york and showed them to the manager of the ,roxbury ,rubber ,company4 ,this gentlemen was so pleased with the ingenuity that ,goodyear had shown in manufacturing these tubes1 that he talked very freely with him and confessed to him that the business was on the verge of ruin1 that the goods had to be tested for a year before they could tell whether they were perfect or not1 and to their surprise1 thousands of dollars worth of goods that they had supposed were all right were coming back to them1 the gum having rotted and made them so offensive that it was necessary to bury them in the ground to get them out of the way4 ,goodyear at once made up his mind to experiment on this gum and see if he could not overcome its stickiness4 ,he1 therefore1 returned to ,philadelphia1 and1 as usual1 met a creditor1 who had him arrested and thrown into prison4 ,while there1 he tried his first experiments with ,india rubber4 ,the gum was very cheap then1 and by heating it and working it in his hands1 he managed to incorporate in it a certain amount of magnesia which produced a beautiful white compound and appeared to take away the stickiness4 ,he therefore thought he had discovered the secret1 and through the kindness of friends was put in the way of further perfecting his invention at a little place in ,new ,haven4 ,the first thing that he made here was shoes1 and he used his own house for grinding room1 calender room1 and vulcanizing department1 and his wife and children helped to make up the goods4 ,his compound at this time was ,india rubber1 lampblack1 and magnesia1 the whole dissolved in turpentine and spread upon the flannel cloth which served as the lining for the shoes4 ,it was not long1 however1 before he discovered that the gum1 even treated this way1 became sticky1 and then those who had supplied the money for the furtherance of these experiments1 completely discouraged1 made up their minds that they could go no further1 and so told the inventor4 ,illustration3 ,,charles ,,goodyear4 ,he1 however1 had no mind to stop here in his experiments1 but1 selling his furniture and placing his family in a quiet boarding place1 he went to ,new ,york1 and there1 in an attic1 helped by a friendly druggist1 continued his experiments4 ,his next step in this line was to compound the rubber with magnesia and then boil it in quicklime and water4 ,this appeared to really solve the problem1 and he made some beautiful goods4 ,at once it was noised abroad that ,india rubber had been so treated that it lost its stickiness1 and he received medals and testimonials and seemed on the high road to success1 till one day he noticed that a drop of weak acid1 falling on the cloth1 neutralized the alkali1 and immediately the rubber was soft again4 ,to see this1 with his knowledge of what rubber should do1 proved to him at once that his process was not a successful one4 ,he therefore continued experimenting1 and after preparing his mixtures in his attic in ,new ,york1 would walk three miles to the mill of a ,mr4 ,pike1 at ,greenwich village1 and there try various experiments4 ,in the line of these1 he discovered that rubber1 dipped in nitric acid1 formed a surface cure1 and he made a great many goods with this acid cure which were spoken of1 and which even received a letter of commendation from ,andrew ,jackson4 ,the constant and varied experiments that ,goodyear went through with affected his health more or less1 and at one time he came very near being suffocated by gas generated in his laboratory4 ,that he did not die then everybody knows1 but he was thrown then into a fever by the accident and came very near losing his life4 ,it was there that he formed an acquaintance with ,dr4 ,bradshaw1 who was very much pleased with the samples of rubber goods that he saw in ,goodyear's room1 and when the doctor went to ,europe he took them with him1 where they attracted a great deal of attention1 but beyond that nothing was done about them4 ,now that he appeared to have success1 he found no difficulty in obtaining a partner1 and together the two gentlemen fitted up a factory and began to make clothing1 life preservers1 rubber shoes1 and a great variety of rubber goods4 ,they also had a large factory1 with special machinery1 built at ,staten ,island1 where he removed his family and again had a home of his own4 ,just about this time1 when everything looked bright1 the great panic of #ahcf-ahcg came1 and swept away the entire fortune of his associate and left ,goodyear without a cent1 and no means of earning one4 ,his next move was to go to ,boston1 where he became acquainted with ,j4 ,haskins1 of the ,roxbury ,rubber ,company1 and found in him a firm friend1 who loaned him money and stood by him when no one would have anything to do with the visionary inventor4 ,mr4 ,chaffee was also exceedingly kind and ever ready to lend a listening ear to his plans1 and to also assist him in a pecuniary way4 ,it was about this time that it occurred to ,mr4 ,chaffee that much of the trouble that they had experienced in working ,india rubber might come from the solvent that was used4 ,he therefore invented a huge machine for doing the mixing by mechanical means4 ,the goods that were made in this way were beautiful to look at1 and it appeared1 as it had before1 that all difficulties were overcome4 ,goodyear discovered a new method for making rubber shoes and got a patent on it1 which he sold to the ,providence ,company1 in ,rhode ,island4 ,the secret of making the rubber so that it would stand heat and cold and acids1 however1 had not been discovered1 and the goods were constantly growing sticky and decomposing and being returned4 ,in #ahch he1 for the first time1 met ,nathaniel ,hayward1 who was then running a factory in ,woburn4 ,some time after this ,goodyear himself moved to ,woburn1 all the time continuing his experiments4 ,he was very much interested in ,hayward's sulphur experiments for drying rubber1 but it appears that neither of them at that time appreciated the fact that it needed heat to make the sulphur combine with the rubber and to vulcanize it4 ,the circumstances attending the discovery of his celebrated process is thus described by ,mr4 ,goodyear himself in his book1 ,gum ,elastic4 ,it will be observed that he makes use of the third person in all references to himself3 ,in the summer of #ahch he became acquainted with ,mr4 ,nathaniel ,hayward1 of ,woburn1 ,mass41 who had been employed as the foreman of the ,eagle ,company at ,woburn1 where he had made use of sulphur by impregnating the solvent with it4 ,it was through him that the writer 7,charles ,goodyear1 who makes use all through his book of the third person7 received the first knowledge of the use of sulphur as a drier of gum elastic4 ,mr4 ,hayward was left in possession of the factory which was abandoned by the ,eagle ,company4 ,soon after this it was occupied by the writer1 who employed him for the purpose of manufacturing life preservers and other articles by the acid gas process4 ,at this period he made many novel and useful applications of this substance4 ,among other fancy articles he had newspapers printed on the gum elastic drapery1 and the improvement began to be highly appreciated4 ,he therefore now entered1 as he thought1 upon a successful career for the future4 ,a far different result awaited him4 ,it was supposed by others as well as himself that a change was wrought through the mass of the goods acted upon by the acid gas1 and that the whole body of the article was made better than the native gum4 ,the surface of the goods really was so1 but owing to the eventual decomposition of the goods beneath the surface1 the process was pronounced by the public a complete failure4 ,thus instead of realizing the large fortune which by all acquainted with his prospects was considered certain1 his whole invention would not bring him a week's living4 ,he was obliged for the want of means to discontinue manufacturing1 and ,mr4 ,hayward left his employment4 ,the inventor now applied himself alone1 with unabated ardor and diligence1 to detect the cause of his misfortune and if possible to retrieve the lost reputation of his invention4 ,on one occasion he made some experiments to ascertain the effect of heat upon the same compound that had decomposed in the articles previously manufactured1 and was surprised to find that the specimen1 being carelessly brought in contact with a hot stove1 charred like leather4 ,he endeavored to call the attention of his brother as well as some other individuals who were present1 and who were acquainted with the manufacture of gum elastic1 to this effect as remarkable and unlike any before known1 since gum elastic always melted when exposed to a high degree of heat4 ,the occurrence did not at the time appear to them to be worthy of notice4 ,it was considered as one of the frequent appeals that he was in the habit of making in behalf of some new experiment4 ,he1 however1 directly inferred that if the process of charring could be stopped at the right point1 it might divest the gum of its native adhesiveness throughout1 which would make it better than the native gum4 ,he made another trial of heating a similar fabric1 before an open fire4 ,the same effect1 that of charring the gum1 followed1 but there were further and very satisfactory indications of ultimate success in producing the desired result1 as upon the edge of the charred portions of the fabric there appeared a line1 or border1 that was not charred1 but perfectly cured4 ,these facts have been stated precisely as they occurred in reference to the acid gas1 as well as the vulcanizing process4 ,the incidents attending the discovery of both have a strong resemblance1 so much so they may be considered parallel cases4 ,it being now known that the results of the vulcanizing process are produced by means and in a manner which would not have been anticipated from any reasoning on the subject1 and that they have not yet been satisfactorily accounted for1 it has been sometimes asked1 how the inventor came to make the discovery8 ,the answer has already been given4 ,it may be added that he was many years seeking to accomplish this object1 and that he allowed nothing to escape his notice that related to the subject4 ,like the falling of an apple1 it was suggestive of an important fact to one whose mind was previously prepared to draw an inference from any occurrence which might favor the object of his research4 ,while the inventor admits that these discoveries were not the results of scientific chemical investigations1 he is not willing to admit that they were the result of what is commonly termed accident2 he claims them to be the result of the closest application and observation4 ,the discoloring and charring of the specimens proved nothing and discovered nothing of value1 but quite the contrary1 for in the first instance1 as stated in the acid gas improvement1 the specimen acted upon was thrown away as worthless and left for some time2 in the latter instance1 the specimen that was charred was in like manner disregarded by others4 ,it may1 therefore1 be considered as one of those cases where the leading of the ,creator providentially aids his creatures1 by what are termed 'accidents1' to attain those things which are not attainable by the powers of reasoning he has conferred on them4 ,now that ,goodyear was sure that he had the key to the intricate puzzle that he had worked over for so many years1 he began at once to tell his friends about it and to try to secure capital1 but they had listened to their sorrow so many times that his efforts were futile4 ,for a number of years be struggled and experimented and worked along in a small way1 his family suffering with himself the pangs of the extremest poverty4 ,at last he went to ,new ,york and showed some of his samples to ,william ,ryder1 who1 with his brother ,emory1 at once appreciated the value of the discovery and started in to manufacturing4 ,even here ,goodyear's bad luck seemed to follow him1 for the ,ryder ,bros4 failed and it was impossible to continue the business4 ,he had1 however1 started a small factory at ,springfield1 ,mass41 and his brother-in-law1 ,mr4 ,de ,forest1 who was a wealthy woolen manufacturer1 took ,ryder's place1 and the work of making the invention practical was continued4 ,in #ahdd it was so far perfected that ,goodyear felt it safe to take out a patent4 ,the factory at ,springfield was run by his brothers1 ,nelson and ,henry4 ,in #ahdc ,henry started one in ,naugatuck1 and in #ahdd introduced mechanical mixing in place of the mixture by the use of solvents4 ,in the year #aheb ,goodyear went to ,europe1 a trip that he had long planned1 and saw ,hancock1 then in the employ of ,charles ,macintosh ,co4 ,hancock admitted in evidence that the first piece of vulcanized rubber he ever saw came from ,america1 but claimed to have reinvented vulcanization and secured patents in ,great ,britain1 but it is a remarkable fact that ,charles ,goodyear's ,french patent was the first publication in ,europe of this discovery4 ,in #aheb a ,french company were licensed by ,mr4 ,goodyear to make shoes1 and a great deal of interest was felt in the new business4 ,in #ahee the ,french emperor gave to ,charles ,goodyear the grand medal of honor and decorated him with the cross of the legion of honor in recognition of his services as a public benefactor1 but the ,french courts subsequently set aside his ,french patents on the ground of the importation of vulcanized goods from ,america by licenses under the ,united ,states patents4 ,he died ,july #a1 #ahfj1 at the ,fifth ,avenue ,hotel1 ,new ,york ,city4--,india ,rubber ,world4 99 99 99 99 99 ,continued from ,,supplement1 ,no4 #ghf1 page #abeeh4 ,,the ,,electromagnet4 ,footnote3 ,lectures delivered before the ,society of ,arts1 ,london1 #ahij4 ,from the ,journal of the ,society4 ,,by ,,professor ,,silvanus ,p4 ,,thompson1 ,d4 ,,sc41 ,b4,a41 ,m4,i4,e4,e4 ,,iii4 ,,researches ,,of ,,professor ,,hughes4 ,illustration3 ,,fig4 #ea4--;,,hughes' ,,electromagnet4 ,his object was to find out the best form of electromagnet1 the best distance between the poles1 and the best form of armature for the rapid work required in ,hughes' printing telegraphs4 ,one word about ,hughes' magnets4 ,this diagram 7,fig4 #ea7 shows the form of the well known ,hughes' electromagnet4 ,i feel almost ashamed to say those words well known1 because on the ,continent everybody knows what you mean by a ,hughes' electromagnet4 ,in ,england scarcely anyone knows what you mean4 ,englishmen do not even know that ,professor ,hughes has invented a special form of electromagnet4 ,hughes' special form is this3 ,a permanent steel magnet1 generally a compound one1 having soft iron pole pieces1 and a couple of coils on the pole pieces only4 ,as ,i have to speak of ,hughes' special contrivance among the mechanisms that will occupy our attention later on1 ,i only now refer to this magnet in one particular4 ,if you wish a magnet to work rapidly1 you will secure the most rapid action1 not when the coils are distributed all along1 but when they are heaped up near1 not necessarily entirely on1 the poles4 ,hughes made a number of researches to find out what the right length and thickness of these pole pieces should be4 ,it was found an advantage not to use too thin pole pieces1 otherwise the magnetism from the permanent magnet did not pass through the iron without considerable reluctance1 being choked by insufficiency of section3 also not to use too thick pieces1 otherwise they presented too much surface for leakage across from one to the other4 ,eventually a particular length was settled upon1 in proportion about six times the diameter1 or rather longer4 ,in the further researches that ,hughes made he used a magnet of shorter form1 not shown here1 more like those employed in relays1 and with an armature from #b to #c millimeters thick1 #a centimeter wide and #e centimeters long4 ,the poles were turned over at the top toward one another4 ,hughes tried whether there was any advantage in making those poles approach one another1 and whether there was any advantage in having as long an armature as #e centimeters4 ,he tried all the different kinds1 and plotted out the results of observations in curves1 which could be compared and studied4 ,his object was to ascertain the conditions which would give the strongest pull1 not with a steady current1 but with such currents as were required for operating his printing telegraph instruments2 currents which lasted but one to twenty hundredths of a second4 ,he found it was decidedly an advantage to shorten the length of the armature1 so that it did not protrude far over the poles4 ,in fact1 he got a sufficient magnetic circuit to secure all the attractive power that he needed1 without allowing as much chance of leakage as there would have been had the armature extended a longer distance over the poles4 ,he also tried various forms of armature having very various cross sections4 ,,position ,,and ,,form ,,of ,,armature4 ,in one of ,du ,moncel's papers on electromagnets#a you will also find a discussion on armatures1 and the best forms for working in different positions4 ,among other things in ,du ,moncel you will find this paradox3 that whereas using a horseshoe magnet with fat poles1 and a flat piece of soft iron for armature1 it sticks on far tighter when put on edgeways2 on the other hand1 if you are going to work at a distance1 across air1 the attraction is far greater when it is set flatways4 ,i explained the advantage of narrowing the surfaces of contact by the law of traction1 ,b1 coming in4 ,why should we have for action at a distance the greater advantage from placing the armature flatway to the poles8 ,it is simply that you thereby reduce the reluctance offered by the air gap to the flow of the magnetic lines4 ,du ,moncel also tried the difference between round armatures and flat ones1 and found that a cylindrical armature was only attracted about half as strongly as a prismatic armature having the same surface when at the same distance4 ,let us examine this fact in the light of the magnetic circuit4 ,the poles are flat4 ,you have at a certain distance away a round armature2 there is a certain distance between its nearest side and the polar surfaces4 ,if you have at the same distance away a flat armature having the same surface1 and1 therefore1 about the same tendency to leak1 why do you get a greater pull in this case than in that8 ,i think it is clear that if they are at the same distance away1 giving the same range of motion1 there is a greater magnetic reluctance in the case of the round armature1 although there is the same periphery1 because1 though the nearest part of the surface is at the prescribed distance1 the rest of the under surface is farther away2 so that the gain found in substituting an armature with a flat surface is a gain resulting from the diminution in the resistance offered by the air gap4 ,footnote #a3 ,la ,lumiere ,electrique1 vol4 ii4 ,,pole ,,pieces ,,on ,,horseshoe ,,magnets4 ,another of ,du ,moncel's researches#b relates to the effect of polar projections or shoes--movable pole pieces1 if you like--upon a horseshoe electromagnet4 ,the core of this magnet was of round iron #d centimeters in diameter1 and the parallel limbs were #aj centimeters long and #f centimeters apart4 ,the shoes consisted of two flat pieces of iron slotted out at one end1 so that they could be slid along over the poles and brought nearer together4 ,the attraction exerted on a flat armature across air gaps #b millimeters thick was measured by counterpoising4 ,exciting this electromagnet with a certain battery1 it was found that the attraction was greatest when the shoes were pushed to about #ae millimeters1 or about one-quarter of the interpolar distance1 apart4 ,the numbers were as follows3 ,distance between shoes4 ,attraction1 ,millimeters4 in grammes4 #b #ijj #aj #a1jab #ae #a1jbe #be #ife #dj #hij #fj #eej ,footnote #b3 ,la ,lumiere ,electrique1 vol4 iv41 p4 #abi4 ,with a stronger battery the magnet without shoes had an attraction of #hhe grammes1 but with the shoes #ae millimeters apart1 #a1aie grammes4 ,when one pole only was employed1 the attraction1 which was #hh grammes without a shoe1 was diminished by adding a shoe to #ci grammes6 ,,contrast ,,between ,,electromagnets ,,and ,,permanent ,,magnets4 ,now ,i want particularly to ask you to guard against the idea that all these results obtained from electromagnets are equally applicable to permanent magnets of steel2 they are not1 for this simple reason4 ,with an electromagnet1 when you put the armature near1 and make the magnetic circuit better1 you not only get more magnetic lines going through that armature1 but you get more magnetic lines going through the whole of the iron4 ,you get more magnetic lines round the bend when you put an armature on to the poles1 because you have a magnetic circuit of less reluctance with the same external magnetizing power in the coils acting around it4 ,therefore1 in that case1 you will have a greater magnetic flux all the way round4 ,the data obtained with the electromagnet 7,fig4 #db71 with the exploring coil1 ,c1 on the bend of the core1 where the armature was in contact1 and when it was removed are most significant4 ,when the armature was present it multiplied the total magnetic flow tenfold for weak currents and nearly threefold for strong currents4 ,but with a steel horseshoe1 magnetized once for all1 the magnetic lines that flow around the bend of the steel are a fixed quantity1 and1 however much you diminish the reluctance of the magnetic circuit1 you do not create or evoke any more4 ,when the armature is away the magnetic lines arch across1 not at the ends of the horseshoe only1 but from its flanks2 the whole of the magnetic lines leaking somehow across the space4 ,where you have put the armature on1 these lines1 instead of arching out into space as freely as they did1 pass for the most part along the steel limbs and through the iron armature4 ,you may still have a considerable amount of leakage1 but you have not made one line more go through the bent part4 ,you have absolutely the same number going through the bend with the armature off as with the armature on4 ,you do not add to the total number by reducing the magnetic reluctance1 because you are not working under the influence of a constantly impressed magnetizing force4 ,by putting the armature on to a steel horseshoe magnet you only collect the magnetic lines1 you do not multiply them4 ,this is not a matter of conjecture4 ,a group of my students have been making experiments in the following way3 ,they took this large steel horseshoe magnet 7,fig4 #eb71 the length of which1 from end to end1 through the steel1 is #db inches4 ,a light1 narrow frame was constructed so that it could be slipped on over the magnet1 and on it were wound #cj turns of fine wire1 to serve as an exploring coil4 ,the ends of this coil were carried to a distant part of the laboratory1 and connected to a sensitive ballistic galvanometer4 ,the mode of experimenting is as follows3 ,the coil is slipped on over the magnet 7or over its armature7 to any desired position4 ,the armature of the magnet is placed gently upon the poles1 and time enough is allowed to elapse for the galvanometer needle to settle to zero4 ,the armature is then suddenly detached4 ,the first swing measures the change1 due to removing the armature1 in the number of magnetic lines that pass through the coil in the particular position4 ,illustration3 ,,fig4 #eb4--;,,experiment ,,with ,,permanent ,,magnet4 ,i will roughly repeat the experiment before you3 ,the spot of light on the screen is reflected from my galvanometer at the far end of the table4 ,i place the exploring coil just over the pole1 and slide on the armature2 then close the galvanometer circuit4 ,now ,i detach the armature1 and you observe the large swing4 ,i shift the exploring coil1 right up to the bend2 replace the armature2 wait until the spot of light is brought to rest at the zero of the scale4 ,now1 on detaching the armature1 the movement of the spot of light is quite imperceptible4 ,in our careful laboratory experiments1 the effect was noticed inch by inch all along the magnet4 ,the effect when the exploring coil was over the bend was not as great as #a-cjjjth part of the effect when the coil was hard up to the pole4 ,we are1 therefore1 justified in saying that the number of magnetic lines in a permanently magnetized steel horseshoe magnet is not altered by the presence or absence of the armature4 ,you will have noticed that ,i always put on the armature gently4 ,it does not do to slam on the armature2 every time you do so1 you knock some of the so-called permanent magnetism out of it4 ,but you may pull off the armature as suddenly as you like4 ,it does the magnet good rather than harm4 ,there is a popular superstition that you ought never to pull off the keeper of a magnet suddenly4 ,on investigation1 it is found that the facts are just the other way4 ,you may pull off the keeper as suddenly as you like1 but you should never slam it on4 ,from these experimental results ,i pass to the special design of electromagnets for special purposes4 ,,electromagnets ,,for ,,maximum ,,traction4 ,these have already been dealt with in the preceding lecture2 the characteristic feature of all the forms suitable for traction being the compact magnetic circuit4 ,several times it has been proposed to increase the power of electromagnets by constructing them with intermediate masses of iron between the central core and the outside1 between the layers of windings4 ,all these constructions are founded on fallacies4 ,such iron is far better placed either right inside the coils or right outside them1 so that it may properly constitute a part of the magnetic circuit4 ,the constructions known as ,camacho's and ,cance's1 and one patented by ,mr4 ,s4,a4 ,varley1 in #ahgg1 belonging to this delusive order of ideas1 are now entirely obsolete4 ,another construction which is periodically brought forward as a novelty is the use of iron windings of wire or strip in place of copper winding4 ,the lower electric conductivity of iron1 as compared with copper1 makes such a construction wasteful of exciting power4 ,to apply equal magnetizing power by means of an iron coil implies the expenditure of about six times as many watts as need be expended if the coil is of copper4 ,,electromagnets ,,for ,,maximum ,,range ,,of ,,attraction4 ,we have already laid down the principle which will enable us to design electromagnets to act at a distance4 ,we want our magnet to project1 as it were1 its force across the greatest length of air gap4 ,clearly1 then1 such a magnet must have a very large magnetizing power1 with many ampere turns upon it1 to be able to make the required number of magnetic lines pass across the air resistance4 ,also it is clear that the poles must not be too close together for its work1 otherwise the magnetic lines at one pole will be likely to curl round and take short cuts to the other pole4 ,there must be a wider width between the poles than is desirable in electromagnets for traction4 ,,electromagnets ,,of ,,minimum ,,weight4 ,in designing an apparatus to put on board a boat or a balloon1 where weight is a consideration of primary importance1 there is again a difference4 ,there are three things that come into play--iron1 copper1 and electric current4 ,the current weighs nothing1 therefore1 if you are going to sacrifice everything else to weight1 you may have comparatively little iron1 but you must have enough copper to be able to carry the electric current2 and under such circumstances you must not mind heating your wires nearly red hot to pass the biggest possible current4 ,provide as little copper as you conveniently can1 sacrificing economy in that case to the attainment of your object2 but1 of course1 you must use fireproof material1 such as asbestos1 for insulating1 instead of cotton or silk4 ,a ,,useful ,,guiding ,,principle4 ,in all cases of design there is one leading principle which will be found of great assistance1 namely1 that a magnet always tends so to act as though it tried to diminish the length of its magnetic circuit4 ,it tries to grow more compact4 ,this is the reverse of that which holds good with an electric current4 ,the electric circuit always tries to enlarge itself1 so as to inclose as much space as possible1 but the magnetic circuit always tries to make itself as compact as possible4 ,armatures are drawn in as near as can be1 to close up the magnetic circuit4 ,many two-pole electromagnets show a tendency to bend together when the current is turned on4 ,one form in particular1 which was devised by ,ruhmkorff for the purpose of repeating ,faraday's celebrated experiment on the magnetic rotation of polarized light1 is liable to this defect4 ,indeed1 this form of electromagnet is often designed very badly1 the yoke being too thin1 both mechanically and magnetically1 for the purpose which it has to fulfill4 ,here is a small electric bell1 constructed by ,wagener1 of ,wiesbaden1 the construction of which illustrates this principle4 ,the electromagnet1 a horseshoe1 lies horizontally2 its poles are provided with protruding curved pins of brass4 ,through the armature are drilled two holes1 so that it can be hung upon the two brass pins2 and when so hung up it touches the ends of the iron cores just at one edge1 being held from more perfect contact by a spring4 ,there is no complete gap1 therefore1 in the magnetic circuit4 ,when the current comes and applies a magnetizing power1 it finds the magnetic circuit already complete in the sense that there are no absolute gaps4 ,but the circuit can be bettered by tilting the armature to bring it flat against the polar ends1 that being indeed the mode of motion4 ,this is a most reliable and sensitive pattern of bell4 ,illustration3 ,,fig4 #ec4--;,,electromagnetic ,,pop-,,gun4 ,electromagnetic ,pop-gun4--,here is another curious illustration of the tendency to complete the magnetic circuit4 ,here is a tubular electromagnet 7,fig4 #ec71 consisting of a small bobbin1 the core of which is an iron tube about two inches long4 ,there is nothing very unusual about it2 it will stick on1 as you see1 to pieces of iron when the current is turned on4 ,it clearly is an ordinary electromagnet in that respect4 ,now suppose ,i take a little round rod of iron1 about an inch long1 and put it into the end of the tube1 what will happen when ,i turn on my current8 ,in this apparatus as it stands1 the magnetic circuit consists of a short length of iron1 and then all the rest is air4 ,the magnetic circuit will try to complete itself1 not by shortening the iron1 but by lengthening it2 by pushing the piece of iron out so as to afford more surface for leakage4 ,that is exactly what happens2 for1 as you see1 when ,i turn on the current1 the little piece of iron shoots out and drops down4 ,you see that little piece of iron shoot out with considerable force4 ,it becomes a sort of magnetic popgun4 ,this is an experiment which has been twice discovered4 ,i found it first described by ,count ,du ,moncel1 in the pages of ,la ,lumiere ,electrique1 under the name of the pistolet electromagnetique2 and ,mr4 ,shelford ,bidwell invented it independently4 ,i am indebted to him for the use of this apparatus4 ,he gave an account of it to the ,physical ,society1 in #ahhe1 but the reporter missed it1 ,i suppose1 as there is no record in the society's proceedings4 ,,electromagnets ,,for ,,use ,,with ,,alternating ,,currents4 ,when you are designing electromagnets for use with alternating currents1 it is necessary to make a change in one respect1 namely1 you must so laminate the iron that internal eddy currents shall not occur2 indeed1 for all rapid-acting electromagnetic apparatus it is a good rule that the iron must not be solid4 ,it is not usual with telegraphic instruments to laminate them by making up the core of bundles of iron plates or wires1 but they are often made with tubular cores1 that is to say1 the cylindrical iron core is drilled with a hole down the middle1 and the tube so formed is slit with a saw cut to prevent the circulation of currents in the substance of the tube4 ,now when electromagnets are to be employed with rapidly alternating currents1 such as are used for electric lighting1 the frequency of the alternations being usually about #ajj periods per second1 slitting the cores is insufficient to guard against eddy currents2 nothing short of completely laminating the cores is a satisfactory remedy4 ,i have here1 thanks to the ,brush ,electric ,engineering ,company1 an electromagnet of the special form that is used in the ,brush arc lamp when required for the purpose of working in an alternating current circuit4 ,it has two bobbins that are screwed up against the top of an iron box at the head of the lamp4 ,the iron slab serves as a kind of yoke to carry the magnetism across the top4 ,there are no fixed cores ,in the bobbins1 which are entered by the ends of a pair of yoked plungers4 ,now in the ordinary ,brush lamp for use with a steady current1 the plungers are simply two round pieces of iron tapped into a common yoke2 but for alternate current working this construction must not be used1 and instead a ,u-shaped double plunger is used1 made up of laminated iron1 riveted together4 ,of course it is no novelty to use a laminated core2 that device1 first used by ,joule1 and then by ,cowper1 has been repatented rather too often during the past fifty years to be considered as a recent invention4 ,the alternate rapid reversals of the magnetism in the magnetic field of an electromagnet1 when excited by alternating electric currents1 sets up eddy currents in every piece of undivided metal within range4 ,all frames1 bobbin tubes1 bobbin ends1 and the like1 must be most carefully slit1 otherwise they will overheat4 ,if a domestic flat iron is placed on the top of the poles of a properly laminated electromagnet1 supplied with alternating currents1 the flat iron is speedily heated up by the eddy currents that are generated internally within it4 ,the eddy currents set up by induction in neighboring masses of metal1 especially in good conducting metals such as copper1 give rise to many curious phenomena4 ,for example1 a copper disk or copper ring placed over the pole of a straight electromagnet so excited is violently repelled4 ,these remarkable phenomena have been recently investigated by ,professor ,elihu ,thomson1 with whose beautiful and elaborate researches we have lately been made conversant in the pages of the technical journals4 ,he rightly attributes many of the repulsion phenomena to the lag in phase of the alternating currents thus induced in the conducting metal4 ,the electromagnetic inertia1 or self-inductive property of the electric circuit1 causes the currents to rise and fall later in time than the electromotive forces by which they are occasioned4 ,in all such cases the impedance which the circuit offers is made up of two things--resistance and inductance4 ,both these causes tend to diminish the amount of current that flows1 and the inductance also tends to delay the flow4 ,,electromagnets ,,for ,,quickest ,,action4 ,i have already mentioned ,hughes' researches on the form of electromagnet best adapted for rapid signaling4 ,i have also incidentally mentioned the fact that where rapidly varying currents are employed1 the strength of the electric current that a given battery can yield is determined not so much by the resistance of the electric circuit as by its electric inertia4 ,it is not a very easy task to explain precisely what happens to an electric circuit when the current is turned on suddenly4 ,the current does not suddenly rise to its full value1 being retarded by inertia4 ,the ordinary law of ,ohm in its simple form no longer applies2 one needs to apply that other law which bears the name of the law of ,helmholtz1 the use of which is to give us an expression1 not for the final value of the current1 but for its value at any short time1 t1 after the current has been turned on4 ,the strength of the current after a lapse of a short time1 t1 cannot be calculated by the simple process of taking the electromotive force and dividing it by the resistance1 as you would calculate steady currents4 ,in symbols1 ,helmholtz's law is3 it ,e_/,r 7 #a - e-7,r_/,l7t 7 ,in this formula it means the strength of the current after the lapse of a short time t2 ,e is the electromotive force2 ,r1 the resistance of the whole circuit2 ,l1 its coefficient of self-induction2 and e the number #b4gahc1 which is the base of the ,napierian logarithms4 ,let us look at this formula2 in its general form it resembles ,ohm's law1 but with a new factor1 namely1 the expression contained within the brackets4 ,the factor is necessarily a fractional quantity1 for it consists of unity less a certain negative exponential1 which we will presently further consider4 ,if the factor within brackets is a quantity less than unity1 that signifies that it will be less than ,e ,r4 ,now the exponential of negative sign1 and with negative fractional index1 is rather a troublesome thing to deal with in a popular lecture4 ,our best way is to calculate some values1 and then plot it out as a curve4 ,when once you have got it into the form of a curve1 you can begin to think about it1 for the curve gives you a mental picture of the facts that the long formula expresses in the abstract4 ,accordingly we will take the following case4 ,let ,e #b volts2 ,r #a ohm2 and let us take a relatively large self-induction1 so as to exaggerate the effect2 say let ,l #aj quads4 ,this gives us the following3 t7sec47 e7,r_/,l7t it ------------------------------------- #j #a #j #a #a4aje #j4iej #b #a4bba #a4haj #e #a4fdi #c4icf #aj #b4gah #f4cdc #bj #g4chi #h4fdf #cj #bj4jh #i4eja #fj #djc4d #i4ige #abj #afbjj4j #i4iii ---------------------------------------- ,in this case the value of the steady current as calculated by ,ohm's law is #aj amperes1 but ,helmholtz's law shows us that with the great self-induction which we have assumed to be present1 the current1 even at the end of #cj seconds1 has only risen up to within #e percent4 of its final value2 and only at the end of two minutes has practically attained full strength4 ,these values are set out in the highest curve in ,fig4 #ed1 in which1 however1 the further supposition is made that the number of spirals1 ,s1 in the coils of the electromagnet is #ajj1 so that when the current attains its full value of #aj amperes1 the full magnetizing power will be ,si #ajjj4 ,it will be noticed that the curve rises from zero at first steeply and nearly in a straight line1 then bends over1 and then becomes nearly straight again1 as it gradually rises to its limiting value4 ,the first part of the curve--that relating to the strength of the current after very small interval of time--is the period within which the strength of the current is governed by inertia 7i4e41 the self-induction7 rather than by resistance4 ,in reality the current is not governed either by the self-induction or by the resistance alone1 but by the ratio of the two4 ,this ratio is sometimes called the time constant of the circuit1 for it represents the time which the current takes in that circuit to rise to a definite fraction of its final value4 ,e #aj r #a ,r #ajj ,l #aj ,si #ajjj 44------------------------------- 4 --------- 4 4---- 4 4- #b ,,in ,,series 4 4- - 43 - 3 43 4 3 #ejj 4 3 - -3--------------------------- 4 3 4- - 3 #b ,,in ,,parallel 4 34 - 3 4 _/ 3 - 3 4 _/ - 3 4 _/ - 3 3 4_/4 3 3 _/33 t #aj #bj #dj #fj #hj #ajj #abj ,,fig4 #ed4--;,,curves ,,of ,,rise ,,of ,,currents4 ,this definite fraction is the fraction 7e - #a7_/;e2 or in decimals1 #j4fcd4 ,all curves of rise of current are alike in general shape1 they differ only in scale1 that is to say1 they differ only in the height to which they will ultimately rise1 and in the time they will take to attain this fraction of their final value4 ,example 7#a74--,suppose ,e #aj2 ,r #bjj ohms2 ,l #h4 ,the final value of the current will be #j4jbe amp4 or #be milliamperes4 ,then the time constant will be #h #djj #a-ejth sec4 ,example 7#b74--,the ,p4,o4 ,standard ,a relay has ,r #djj ohms2 ,l #c4be4 ,it works with #j4e milliampere current1 and therefore will work with #e ,daniell cells through a line of #i1fjj ohms4 ,under these circumstances the time constant of the instrument on short circuit is #j4jjha sec4 ,it will be noted that the time constant of a circuit can be reduced either by diminishing the self-induction or by increasing the resistance4 ,in ,fig4 #ed the position of the time constant for the top curve is shown by the vertical dotted line at #aj seconds4 ,the current will take #aj seconds to rise to #j4fcd of its final value4 ,this retardation of the rise of current is simply due to the presence of coils and electromagnets in the circuit2 the current as it grows being retarded because it has to create magnetic fields in these coils1 and so sets up opposing electromotive forces that prevent it from growing all at once to its full strength4 ,many electricians1 unacquainted with ,helmholtz's law1 have been in the habit of accounting for this by saying that there is a lag in the iron of the electromagnet cores4 ,they tell you that an iron core cannot be magnetized suddenly1 that it takes time to acquire its magnetism4 ,they think it is one of the properties of iron4 ,but we know that the only true time lag in the magnetization of iron1 that which is properly termed viscous hysteresis1 does not amount to any great percentage of the whole amount of magnetization1 takes comparatively a long time to show itself1 and cannot therefore be the cause of the retardation which we are considering4 ,there are also electricians who will tell you that when magnetization is suddenly evoked in an iron bar1 there are induction currents set up in the iron which oppose and delay its magnetization4 ,that they oppose the magnetization is perfectly true1 but if you carefully laminate the iron so as to eliminate eddy currents1 you will find1 strangely enough1 that the magnetism rises still more slowly to its final value4 ,for by laminating the iron you have virtually increased the self-inductive action1 and increased the time constant of the circuit1 so that the currents rise more slowly than before4 ,the lag is not in the iron1 but in the magnetizing current1 and the current being retarded1 the magnetization is of course retarded also4 ,,connecting ,,coils ,,for ,,quickest ,,action4 ,now let us apply these most important though rather intricate considerations to the practical problems of the quick working of the electromagnet4 ,take the case of an electromagnet forming some part of the receiving apparatus of a telegraph system in which it is desired to secure very rapid working4 ,suppose the two coils that are wound upon the horseshoe core are connected together in series4 ,the coefficient of self-induction for these two is four times as great as that of either separately2 coefficients of self-induction being proportional to the square of the number of turns of wire that surround a given core4 ,now if the two coils instead of being put in series are put in parallel1 the coefficient of self-induction will be reduced to the same value as if there were only one coil1 because half the line current 7which is practically unaltered7 will go through each coil4 ,hence the time constant of the circuit when the coils are in parallel will be a quarter of that which it is when the coils are in series2 on the other hand1 for a given line current1 the final magnetizing power of the two coils in parallel is only half what it would be with the coil in series4 ,the two lower curves in ,fig4 #ed illustrate this1 from which it is at once plain that the magnetizing power for very brief currents is greater when the two coils are put in parallel with one another than when they are joined in series4 ,now this circumstance has been known for some time to telegraph engineers4 ,it has been patented several times over4 ,it has formed the theme of scientific papers1 which have been read both in ,france and in ,england4 ,the explanation generally given of the advantage of uniting the coils in parallel is1 ,i think1 fallacious2 namely that the extra currents 7i4e41 currents due to self-induction7 set up in the two coils are induced in such directions as tend to help one another when the coils are in series1 and to neutralize one another when they are in parallel4 ,it is a fallacy1 because in neither case do they neutralize one another4 ,whichever way the current flows to make the magnetism1 it is opposed in the coils while the current is rising1 and helped in the coils while the current is falling1 by the so-called extra currents4 ,if the current is rising in both coils at the same moment1 then1 whether the coils are in series or in parallel1 the effect of self-induction is to retard the rise of the current4 ,the advantage of parallel grouping is simply that it reduces the time constant4 ,,battery ,,grouping ,,for ,,quickest ,,action4 ,one may consider the question of grouping the battery cells from the same point of view4 ,how does the need for rapid working1 and the question of time constant1 affect the best mode of grouping the battery cells8 ,the amateur's rule1 which tells you to so arrange your battery that its internal resistance should be equal to the external resistance1 gives you a result wholly wrong for rapid working4 ,the supposed best arrangement will not give you 7at the expense even of economy7 the best result that might be got out of the given number of cells4 ,let us take an example and calculate it out1 and place the results graphically before our eyes in the form of curves4 ,suppose the line and electromagnet have together a resistance of #f ohms1 and that we have #bd small ,daniell cells1 each of electromotive force say #a volt1 and of internal resistance #d ohms4 ,also let the coefficient of self-induction of the electromagnet and circuit be #f quadrants4 ,when all the cells are in series1 the resistance of the battery will be #if ohms1 the total resistance of the circuit #ajb ohms1 and the full value of the current #j4bce ampere4 ,when all the cells are in parallel1 the resistance of the battery will be #j4acc ohm1 the total resistance #f4acc ohms1 and the full value of the current #j4afb ampere4 ,according to the amateur rule of grouping cells so that internal resistance equals external1 we must arrange the cells in #d parallels1 each having #f cells in series1 so that the internal resistance of the battery will be #f ohms1 total resistance of circuit #ab ohms1 full value of current #j4e ampere4 ,now the corresponding time constants of the circuit in the three cases 7calculated by dividing the coefficient of self-induction by the total resistance7 will be respectively--in series1 #j4jf sec42 in parallel1 #j4e sec42 grouped for maximum steady current1 #j4if sec4 ,from these data we may now draw the three curves1 as in ,fig4 #ee1 wherein the absciss are the values of time in seconds and the ordinates the current4 ,the faint vertical dotted lines mark the time constants in the three cases4 ,it will be seen that when rapid working is required the magnetizing current will rise1 during short intervals of time1 more rapidly if all the cells are put in series than it will do if the cells are grouped according to the amateur rule4 #e 4 4 4 #d ,,maximum 4 ,,output 4 4 #c 4 4 3 ,,all ,,in ,,series -------------------3-------------------- ---------- #b 4- - 3 - - 3 -3 - 3 #a _/ 3 - 3 ,,all ,,in ,,parallel 4 3 4 3 -------- - 3 3 ---------- -----------------------------3---------- --------------------- #j #a #b #c #d #e #f #g #h #i #aj ,,fig4 #ee4--;,,curves ,,of ,,rise ,,of ,,current ,,with ,,different ,,groupings ,,of ,,battery4 ,when they are all put in series1 so that the battery has a much greater resistance than the rest of the circuit1 the current rises much more rapidly1 because of the smallness of the time constant1 although it never attains the same ultimate maximum as when grouped in the other way4 ,that is to say1 if there is self-induction as well as resistance in the circuit1 the amateur rule does not tell you the best way of arranging the battery4 ,there is another mode of regarding the matter which is helpful4 ,self-induction1 while the current is growing1 acts as if there were a sort of spurious addition to the resistance of the circuit2 and while the current is dying away it acts of course in the other way1 as if there were a subtraction from the resistance4 ,therefore you ought to arrange the battery so that the internal resistance is equal to the real resistance of the circuit1 plus the spurious resistance during that time4 ,but how much is the spurious resistance during that time8 ,it is a resistance proportional to the time that has elapsed since the current was turned on4 ,so then it comes to a question of the length of time for which you want to work it4 ,what fraction of a second do you require your signal to be given in8 ,what is the rate of the vibrator of your electric bell8 ,suppose you have settled that point1 and that the short time during which the current is required to rise is called t2 then the apparent resistance at time t after the current is turned on is given by the formula3 ,rt ,r e7,r_/,l7t 7 e7,r_/,l7t - #a 7 ,,time ,,constants ,,of ,,electromagnets4 ,i may here refer to some determinations made by ,m4 ,vaschy1#a respecting the coefficients of self-induction of the electromagnets of a number of pieces of telegraphic apparatus4 ,of these ,i must only quote one result1 which is very significant4 ,it relates to the electromagnet of a ,morse receiver of the pattern habitually used on the ,french telegraph lines4 ,l1 in quadrants4 ,bobbins1 separately1 without iron cores4 #j4bcc and #j4bfe ,bobbins1 separately1 with iron cores4 #a4fe and #a4ga ,bobbins1 with cores joined by yoke1 coils in series #f4cg ,bobbins1 with armature resting on poles4 #aj4fh ,footnote #a3 ,bulletin de la ,societe ,internationale des ,electriciens1 #ahhf4 ,it is interesting to note how the perfecting of the magnetic circuit increases the self-induction4 ,thanks to the kindness of ,mr4 ,preece1 ,i have been furnished with some most valuable information about the coefficients of self-induction1 and the resistance of the standard pattern of relays1 and other instruments which are used in the ,british postal telegraph service1 from which data one is able to say exactly what the time constants of those instruments will be on a given circuit1 and how long in their case the current will take to rise to any given fraction of its final value4 ,here let me refer to a very capital paper by ,mr4 ,preece in an old number of the ,journal of the ,society of ,telegraph ,engineers1 a paper ,on ,shunts1 in which he treats this question1 not as perfectly as it could now be treated with the fuller knowledge we have in #ahij about the coefficients of self-induction1 but in a very useful and practical way4 ,he showed most completely that the more perfect the magnetic circuit is--though of course you are getting more magnetism from your current--the more is that current retarded4 ,mr4 ,preece'e mode of experiment was extremely simple4 ,he observed the throw of the galvanometer when the circuit which contained the battery and the electromagnet was opened by a key which at the same moment connected the electromagnet wires to the galvanometer4 ,the throw of the galvanometer was assumed to represent the extra current which flowed out4 ,fig4 #ef represents a few of the results of ,mr4 ,preece's paper4 _/ -- _/ _/ ,b _/,a ,a _/,b -- ,a ,b ,b ,a ,,fig4 #ef4--;,,electromagnets ,,of ,,relay1 ,,and ,,their ,,effects4 ,take from an ordinary relay a coil1 with its iron core1 half the electromagnet1 so to speak1 without any yoke or armature4 ,connect it up as described1 and observe the throw given to the galvanometer4 ,the amount of throw obtained from the single coil was taken as unity1 and all others were compared with it4 ,if you join up two such coils as they are usually joined1 in series1 but without any iron yoke across the cores1 the throw was #ag4 ,putting the iron yoke across the cores1 to constitute a horseshoe form1 #dif was the throw2 that is to say1 the tendency of this electromagnet to retard the current was #dif times as great as that of the simple coil4 ,but when an armature was put over the top1 the effect ran up to #b1bch4 ,by the mere device of putting the coils in parallel1 instead of in series1 the #b1bch came down to #ejb1 a little less than the quarter value which would have been expected4 ,lastly1 when the armature and yoke were both of them split in the middle1 as is done in fact in all the standard patterns of the ,british postal telegraph relays1 the throw of the galvanometer was brought down from #ejb to #bf4 ,relays so constructed will work excessively rapidly4 ,mr4 ,preece states that with the old pattern of relay having so much self-induction as to give a galvanometer throw of #a1fhh1 the speed of signaling was only from #ej to #fj words per minute1 whereas1 with the standard relays constructed on the new plan1 the speed of signaling is from #djj to #dej words per minute4 ,it is a very interesting and beautiful result to arrive at from the experimental study of these magnetic circuits4 ,,short ,,cores versus ,,long ,,cores4 ,in considering the forms that are best for rapid action1 it ought to be mentioned that the effects of hysteresis in retarding changes in the magnetization of iron cores are much more noticeable in the case of nearly closed magnetic circuits than in short pieces4 ,electromagnets with iron armatures in contact across their poles will retain1 after the current has been cut off1 a very large part of their magnetism1 even if the cores be of the softest of iron4 ,but so soon as the armature is wrenched off1 the magnetism disappears4 ,an air gap in a magnetic circuit always tends to hasten demagnetizing4 ,a magnetic circuit composed of a long air path and a short iron path demagnetizes itself much more rapidly than one composed of a short air path and a long iron path4 ,in long pieces of iron the mutual action of the various parts tends to keep in them any magnetization that they may possess2 hence they are less readily demagnetized4 ,in short pieces1 where these mutual actions are feeble or almost absent1 the magnetization is less stable1 and disappears almost instantly on the cessation of the magnetizing force4 ,short bits and small spheres of iron have no magnetic memory4 ,hence the cause of the commonly received opinion among telegraph engineers that for rapid work electromagnets must have short cores4 ,as we have seen1 the only reason for employing long cores is to afford the requisite length for winding the wire which is necessary for carrying the needful circulation of current to force the magnetism across the air gaps4 ,if1 for the sake of rapidity of action1 length has to be sacrificed1 then the coils must be heaped up more thickly on the short cores4 ,the electromagnets in ,american patterns of telegraphic apparatus usually have shorter cores1 and a relatively greater thickness of winding upon them1 than those of ,european patterns4 99 99 99 99 99 ,,electric ,,erygmascope4 ,the erygmascope is the name of an electric lighting apparatus designed for the examination of the strata of earth traversed by boring apparatus4 ,it consists of a very powerful incandescent lamp inclosed in a metallic cylinder4 ,one of the two semi-cylindrical sides constitutes the reflector1 and the other1 which is of thick glass1 allows of the passage of the luminous rays1 which thus illuminate with great brilliancy the strata of earth traversed by the instrument4 ,the base1 which is inclined at an angle of #de1 is an elliptical mirror1 and the top1 of straight section1 is open in order to permit the observer standing at the mouth of the well1 and provided with a powerful spyglass1 to see in the mirror the image of the earth4 ,the lamp is so mounted that its upwardly emitted rays are intercepted4 ,the whole apparatus is suspended from a long cable1 formed of two conducting wires1 which winds around a windlass with metallic journals which are electrically insulated4 ,these journals communicate1 through the intermedium of two friction springs1 with the conductors on the one hand and1 on the other1 with the poles of an automatic and portable battery4 ,illustration3 ,,the ,,trouve ,,erygmascope4 ,this permits of lowering and raising the apparatus at will1 without derangement1 and without its being necessary to interrupt the light and the observation4--,revue ,industrielle4 99 99 99 99 99 ,a ,,new ,,electric ,,ballistic ,,target4 ,the electrical target usually employed in determining velocities of projectiles consists of a wooden frame on which is strung a copper wire so as to make a continuous circuit arranged in parallel vertical lines about one inch or one and one half inches apart4 ,it frequently happens that a projectile will pass through this target without breaking the circuit1 either by squeezing between the wires or because1 when last repaired1 the target was short-circuited unnoticed1 so that the cutting of the wires did not break the circuit4 ,the repair of this target takes considerable time4 ------------- ------------------------------ _/_/ _/_/ ,c#j ,a ,a ,p _/_/ _/_/ ------------- --------------- ---------------- ,f ,plan4 ,p ,c ,a ,a ,s _/ spring ,s ,section4 ,h _/ _/ ,w ,besides these objections to this target1 another and more serious one is the irregularity in the manner of breaking the circuit4 ,it has been proved that times required for a flat headed and an ogival headed projectile to rupture the current are very different4 ,to remedy these defects a new and very ingenious target has been devised and used with great success at the ,united ,states ,military ,academy at ,west ,point4 ,the top of the target is a wooden strip1 ,f1 on the upper side of which are screwed strips of copper1 ,a ,a1 about #a_/b in4 wide1 and #a_/h in4 thick4 ,the connection between two adjoining strips is made by a copper cartridge1 ,c1 which is dropped in a hole in the frame bored to receive it4 ,this cartridge is the one used in the ,springfield rifle4 ,inside the cartridge is a spiral spring1 ,s1 which1 acting on the bottom of the hole and the head of the cartridge1 tends to make the latter spring up1 and so break the circuit4 ,to the hook1 ,h1 which is attached to the cartridge1 is suspended1 by means of a string1 the lead weight1 ,w1 thus drawing down the cartridge and making the circuit between ,a and ,a'4 ,all the weights being suspended the current comes in through the post1 ,p1 passes along the copper strips and out of the corresponding post on the other end4 ,on firing the projectile cuts a string1 and the spring at once causes the cartridge to spring up1 thus breaking the circuit4 ,it is not possible for the projectile to squeeze between the strings and not break the current1 for in so doing the cartridge is tipped slightly1 which is sufficient1 as it breaks the current on one side4 ,this target is used in connection with the ,boulenge chronograph4 ,two targets are established at a known distance apart1 say #ej ft41 and the time required for the projectile to pass over this distance is determined by finding the difference in the time of cutting of the two targets1 by finding the difference in the time of falling of the two rods1 caused by the demagnetization of two electromagnets in the same circuit with the targets4 ,by means of a disjunctor both rods are dropped at the same time1 the shorter one releasing a knife blade which makes a cut on the longer one4 ,now both rods are hung from the magnets again and the gun is fired4 ,the projectile passes through the first target1 breaks the circuit1 demagnetizes the magnet of the longer rod1 and it begins to fall4 ,on passing through the second target1 the projectile causes the shorter rod to fall4 ,this releases the knife blade1 and a second cut is made4 ,the time corresponding to the distance between these cuts is the time the longer rod was falling before the second rod began to fall or the time between the cutting of the two targets by the projectile4 ,the distance between the cuts is measured1 and the time corresponding to it can easily be found4 ,then the velocity of the projectile is equal to #ej_/t4 ,to repair this target1 strings are prepared in advance of suitable length and looped at both ends1 so that by placing the hook of the cartridge in one loop and that of the weight in the other the repair is quickly made4 ,this target has been used on the ,west ,point proving ground to determine velocities over distances of #ajj ft4 interval to distances of only #i ft4 interval1 and has given most satisfactory results4 99 99 99 99 99 ,continued from ,,supplement1 ,no4 #ghf1 page #abeff4 ,,the ,,outlook ,,for ,,applied ,,entomology4 ,footnote3 ,address of ,dr4 ,c4,v4 ,riley at the annual meeting of the ,association of ,economic ,entomologists1 ,champaign1 ,ills41 ,november #aa to #ad1 #ahij4 ,,legislation4 ,the amount of legislation in different countries that has of late years been deemed necessary or sufficiently important1 in view of injurious insects1 is a striking evidence of the increased attention paid to applied entomology2 and while modern legislation of this kind has been1 on the whole1 far more intelligent than similar efforts in years gone by1 many of the laws passed have nevertheless been unwise1 futile1 and impracticable1 and even unnecessarily oppressive to other interests4 ,the chief danger here is the intervention of politics or political methods4 ,expert counsel should guide our legislators and the steps taken should be thorough in order to be effective4 ,we have had of late years in ,germany very good evidence of the excellent results flowing from thorough methods1 and the recent legislation in ,massachusetts against the gypsy moth 7,ocneria dispar71 which at one time threatened to become farcical1 has1 fortunately1 proved more than usually successful2 the commission appointed to deal with the subject having worked with energy and followed competent advice4 ,,publication4 ,on the question of publication of the results of our labors it is perhaps premature to dwell at length4 ,each of the experiment stations is publishing its own bulletins and reports quite independently of the others1 but after a uniform plan recommended by the association with which we meet here2 and with but one exception that has come to my notice1 another important recommendation of the same association--that these publications shall be void of all personal matter--has been kept in mind4 ,the ,national ,bureau of ,experiment ,stations at ,washington is doing what it can with the means at command to further the general work by issuing the ,experiment ,station ,record1 devoted chiefly to digests of the ,state station bulletins4 ,there is a serious question in my mind as to the utility of ,state digests by the national department of results already published extensively by the different ,states and distributed under government frank to all similar institutions and to whomsoever is interested enough to ask for them4 ,such digests may or may not be intelligently made1 and1 even under the most favorable circumstances1 will hardly serve any other purpose than helping to the reference to the original articles1 and this could undoubtedly be done more satisfactorily to the stations and to the people at large by general and classified indices to all the ,state documents1 made as full as possible and issued at stated intervals4 ,only a small proportion of the bulletins have been so far noticed by digest in this record1 with no particular rule1 so far as ,i can see1 in the selection4 ,in point of fact1 those will be most apt to be noticed whose authors can find time to themselves send or make for the purpose their own abstracts4 ,this is1 perhaps1 inevitable under present arrangements4 ,complete and satisfactory digests of all1 if intelligent and critical1 imply a far greater force than is at present at ,prof4 ,atwater's command4 ,under these circumstances1 it would seem wiser to devote all the energies of the bureau to digests of the similar literature of other countries1 which would be of immense advantage to our people and to the different station workers4 ,judging from the recommendations and resolutions of the general association1 this is the view very generally held1 but except in chemistry and special industries like that of beet sugar1 very little of that kind of work has yet been attempted4 ,what is true of the station publications in general is equally true of special publications4 ,as entomologist of the department1 ,i have been urged to bring together1 at stated intervals1 digests of the entomological publications of the different stations4 ,such digests to be of any value1 however1 should also be critical1 and it were a thankless task for any one to be critic or censor even of that which needs correction or criticism4 ,moreover1 to do this work intelligently would require increase of the divisional force1 which at present is more advantageously employed1 for1 as already intimated1 ,i should have great doubts of the utility of these digests4 ,i believe1 however1 that the division should strive for such increase of means as would justify the periodic publication1 either independently or as a part of the department record1 of general and classified indices to the entomological matter of the station bulletins1 and should work more and more toward giving results from other parts of the world4 ,this could1 perhaps1 best be done by titles of subject and of author so spaced and printed on stout paper that they could be cut and used in the ordinary card catalogue4 ,the recipient could cut and systematically place the titles as fast as received4 ,as to the character of the matter of the entomological bulletins1 it will inevitably be influenced by the needs and demands of the people of the respective ,states1 and while originality should be kept in mind1 there must needs be in the earlier years of the work much restatement of what is already well known4 ,that some results have been published of work which reflects no particular credit upon our calling is a mere incident of the new positions created4 ,yet we may expect marked improvement from year to year in this direction1 and without being invidious1 ,i would cite those of ,prof4 ,gillette's on his spraying experiments and on the plum curculio and plum gouger1 as models of what such bulletins should be4 ,although the resolution offered at our last meeting by ,prof4 ,cook1 to the effect that purely descriptive matter should be excluded from the station bulletins1 met with no favor1 but was laid on the table1 by the general association1 ,i am in full sympathy with this position and am strongly of the opinion that in the ordinary bulletins such purely technical and descriptive matter should be reduced to the necessary minimum consistent with clearness of statement and accuracy1 and that if it is desired1 on the part of the station entomologists1 to issue technical and descriptive papers1 a separate series of bulletins were better instituted for this class of matter4 ,finally1 for results which it is desired to promptly get before the people1 the agricultural press is at our disposal1 and so far as the entomological work of the department of agriculture is concerned1 the periodical bulletin1 ,insect ,life1 was established for this purpose4 ,its columns are open to all station workers1 and ,i would here appeal to the members of the association to help make it1 as far as possible1 national1 by sending brief notes and digests of their work as it progresses4 ,hitherto we have been unable to make as much effort in this direction as we desired1 but in future it is our hope to make the bulletin1 as far as possible1 a national medium through which the results of work done in all parts of the country may quickly be put on record and distributed1 not only to all parts of our own country1 but to all parts of the world4 ,the rapid growth and development of the national department and the multiplication of its divisions have necessitated special modes of publication and rendered the annual report almost an anachronism so far as it pretends to be what it at one time was--a pretty complete report of the scientific and other work of the department4 ,the attempts which ,i have made through the proper authorities to get ,congress to order more pretentious monographic works in quarto volume similar to those issued by other departments of the government have not met with encouragement1 and in this direction many of the stations will1 let us hope1 be able to do better4 ,,co-,,operation4 ,every other subject that might be considered on this occasion must be subordinate to the one great question of co-operation4 ,with the large increase of actual workers in our favorite field1 distributed all over the country1 the necessity for some co-operation and co-ordination must be apparent to every one4 ,just how this should be brought about or in what direction we may work toward it1 will be for this association in its deliberations to decide4 ,nor will ,i venture to anticipate the deliberations and conclusions of the special committee appointed to take the matter into consideration1 beyond the statement that there are many directions in which we can adopt plans for mutual benefit4 ,take1 for instance1 the introduction and dissemination of parasites4 ,how much greater will be the chance of success in any particular case if we have all the different station entomologists interested in some specific plan to be carried out in co-operation with the national department1 which ought to have better facilities of introducing specimens to foreign countries or to different sections of our own country than any of the ,state stations4 ,let us suppose that the fruit growers of one section of the country1 comprising several ,states in area1 need the benefit in their warfare against any particularly injurious insect of such natural enemy or enemies as are known to help the fruit growers of some other section4 ,there will certainly be much greater chances of success in the carrying out of any scheme of introduction if all the workers in the one section may be called upon through some central or national body to help in the introduction and disposition of the desired material into the other section4 ,or1 take the case of the boll worm investigation already alluded to4 ,the chances of success would be much greater if the entomologists in all the ,states interested were to give some attention to such lepidopterous larv as are found to be affected with contagious diseases and to follow out some specific plan of cultivating and transmitting them to the party or parties with whom the actual trials are intrusted4 ,the argument applies with still greater force to any international efforts4 ,i need hardly multiply instances4 ,there is1 it is true1 nothing to prevent any individual station entomologist from requesting co-operation of the other stations1 nor is there anything to prevent the national department from doing likewise2 but in all organization results are more apt to flow from the power to direct rather than from mere liberty to request or to plead4 ,the station entomologist may be engrossed in some line of research which he deems of more importance to the people of his ,state1 and may resent being called upon to divert his energies2 and with no central or national power to decide upon plans of co-operation for the common weal1 we are left to voluntary methods1 mutually devised1 and it is here that this association can1 it seems to me1 most fully justify its organization4 ,and this brings me to the question of ,,the ,,department ,,and ,,the ,,stations4 ,immediately connected with the question of co-operation is the relation of the ,national ,department of ,agriculture and the ,state experiment stations4 ,the relation1 instead of being vital and authoritative1 is1 in reality1 a subordinate one4 ,many persons interested in the advancement of agriculture foresaw the advantage of having experiment stations attached to the ,state agricultural colleges founded under the ,morrill act of #ahfb2 but ,i think that in the minds of most persons the establishment of these stations implied some such connection with the national department as that outlined in an address on ,agricultural ,advancement in the ,united ,states1 which ,i had the honor to deliver in #ahgi before the ,national ,agricultural ,congress1 at ,rochester1 and in which the following language was used3 ,in the light of the past history of the ,german experimental stations and their work1 or of that in our own ,state of ,connecticut1 the expediency of purchasing an experimental farm of large dimensions in the vicinity of ,washington is very questionable4 ,there can be no doubt1 however1 of the value of a good experimental station there that shall have its branches in every ,state of the ,union4 ,the results to flow from such stations will not depend upon the number of acres at command1 and it will be far wiser and more economical for the commissioner to make each agricultural college that accepted the government endowment auxiliary to the national bureau1 so that the experimental farm that is now1 or should be1 connected with each of these institutions might be at its service and under the general management of the superintendent of the main station4 ,there is reason to believe that the directors of these colleges would cheerfully have them constituted as experimental stations under the direction of the department1 and thus help to make it really national--the head of a vast system that should ramify through all parts of the land4444 ,with the different ,state agricultural colleges1 and the ,state agricultural societies1 or boards1 we have every advantage for building up a national bureau of agriculture worthy of the country and its vast productive interests1 and on a thoroughly economical basis1 such as that of ,prussia1 for instance4 ,in short1 the view in mind was something in the nature of that which has since been adopted by our neighbors of the ,north1 where there is a central or national station or farm at ,ottawa and sub-stations or branch farms at ,nappan1 ,nova ,scotia1 ,brandon1 ,manitoba1 ,indian ,head1 ,n4,w4,t41 and ,agassiz1 ,british ,columbia1 all under the able direction of ,mr4 ,william ,saunders1 one of our esteemed fellow workers4 ,it was my privilege to be a good deal with ,mr4 ,saunders when he was in ,europe studying the experience of other countries in this matter1 and the policy finally adopted in ,canada as a result of his labors is an eminently wise one1 preventing some of the difficulties and dangers which beset our plan1 whether as between ,state and nation or college and station4 ,under the present laws and with the vast influence which the ,association of ,agricultural ,colleges and ,experiment ,stations will wield1 both in ,congress and in the different ,states1 there is great danger of transposition1 in this agricultural body politic1 of those parts which in the animal body are denominated head and tail1 and the old saw to the effect that the dog wags the tail because the tail cannot wag the dog1 will find another application4 ,so far as the law goes1 the national department1 which should hold a truly national position toward ,state agricultural institutions depending on federal support1 can do little except by suggestion1 whether in the line of directing plans or in any way co-ordinating or controlling the work of the different stations throughout the country4 ,the men who influenced and shaped the legislation which resulted in the ,hatch bill were careful that the department's function should be to indicate1 not to dictate2 to advise and assist1 not to govern or regulate4 ,we have1 therefore1 to depend on such relationships and such plans of co-operation as will appear advantageous to all concerned1 and these can best be brought about through such associations as are now in convention here4 ,without such plans there is great danger of such waste of energy and means and duplication of results as will bring the work into popular disfavor and invite disintegration1 for already there is a growing feeling that agricultural experiment is and will be subordinated to the ordinary college work in the disposition of the federal appropriations4 ,what is true of the national department as a whole in its connection with the ,state stations is true in a greater or less degree of the different divisions of the department in connection with the different specialists of the stations4 ,with the multiplicity of workers in any given direction in the different ,states1 the necessity for national work lessens4 ,a favorite scheme of mine in the past1 for instance 7and one ,i am glad to say fully indorsed by ,prof4 ,willits71 was to endeavor to have a permanent agent located in every section of the country that was sufficiently distinctive in its agricultural resources and climate1 or1 as a yet further elaboration of the same plan1 one in each of the more important agricultural ,states4 ,the necessity for such ,state agents has been lessened1 if not obviated1 by the ,hatch bill1 and the subsequent modifications looking to permanent appropriations to the ,state stations or colleges1 which give no central power at ,washington4 ,the question then arises1 ,what function shall the national department perform8 ,its influence and field for usefulness have been lessened rather than augmented in the lines of actual investigation in very many directions4 ,many a ,state is already far better equipped both as to valuable surrounding land1 laboratory and library facilities1 more liberal salaries1 and greater freedom from red tape1 administrative routine1 and restrictions as to expenditures1 than we are at ,washington2 and1 except as a directing agent and a useful servant1 ,i cannot see where the future growth of the department's influence is to be outside of those federal functions which are executive4 ,just what that directing influence is to be is the question of the hour1 not only in the broader but in the special sense4 ,the same question1 in a narrower sense1 had arisen in the case of the few ,states which employed ,state entomologists4 ,in the event1 for instance1 of an outbreak of some injurious insect1 or in the event of any particular economic entomological question within the limits of the ,state having such an officer1 the ,united ,states entomologist would naturally feel that any effort on his part would be unnecessary1 or might even be looked upon as an interference4 ,he would feel that there was always danger of mere duplication of observation or experiment1 except where appealed to for aid or co-operation4 ,this is1 perhaps1 true only of insects which are local or sectional1 and is rather a narrow view of the matter1 but it is one brought home from experience1 and is certainly to be considered in our future plans4 ,the favor with which the museum work of the national division was viewed by you at the meeting last ,november and the amount of material sent on for determination would indicate that the building up of a grand national reference collection will be most useful to the station workers4 ,but to do this satisfactorily we need your co-operation1 and ,i appeal to all entomologists to aid in this effort by sending duplicates of their types to ,washington1 and thus more fully insuring against ultimate loss thereof4 ,,status ,,of ,,our ,,society4 ,this train of thought brings up the question of the status of our society with the station entomologists as represented by the committee of the general association4 ,those of us who had desired a national association for the various purposes for which such associations are formed1 felt1 ,i believe1 if ,i may speak for them1 that the creation of the different experimental stations rendered such an organization feasible4 ,your organization at ,toronto and the constitution adopted and amended at the meeting at ,washington all indicate that the chief object was the advancement of our chosen work and that the strength of the association would come from the experiment station entomologists4 ,there was then no other organization of the kind1 nor any intimation that such a one would be founded4 ,some of us therefore were surprised to learn from the circular sent out by ,prof4 ,forbes1 its chairman1 that the committee appointed by the association of agricultural colleges and experiment stations1 and through which we had hoped to communicate and co-operate with that association1 was not in the proper sense a committee1 but a section which has prepared 7and in fact was required by the executive committee and the rules of the superior body to prepare7 a programme of papers and discussions for the meeting to be held at the same time and place with our own4 ,i cannot but feel that this is in some respects a misfortune1 and it will devolve upon you to decide upon several questions of importance that will materially affect our future existence4 ,that there is not room for two national organizations having the same objects in view and meeting at the same time and place goes1 ,i think1 without saying2 and if the committee of the general association is to be anything more than a committee in the proper sense of the word1 or if it is to assume with or without formal constitution the functions of our own association1 then our own must necessarily be crippled1 and to do any good at all must meet at a different time and a different place4 ,a committee or section1 or whatever it may be called1 of the general association with which we meet1 would preclude active membership of any but those who come within the constitution of that body4 ,our ,canadian friends and many others who have identified themselves with applied entomology1 and do not belong to any of our ,state or government institutions1 would be debarred from active representation1 however liberal the association may have been in inviting such to participate1 without power to vote in its deliberations4 ,our own association has1 or should have1 no such limitations4 ,some of us who are entitled to membership in both bodies may feel indifferent as to the course finally decided upon1 and that it will not make any difference whether we have an outside and independent organization1 as that of the association of official chemists1 or whether we do1 as did the botanists and horticulturists1 waive independence in favor of more direct connection with the general association1 provided there is some way whereby the committees of the general association are given sufficient latitude and time to properly present their papers and deliberate2 but there are others who feel more sensitive as to their action and are more immediately influenced by the feelings of the main body4 ,i hope that whatever action be taken at this meeting1 the general good and the promotion of economic entomology will be kept in mind and that no sectional or personal feeling will be allowed to influence our deliberations4 ,,suggestion ,,and ,,comment4 ,you will1 ,i know1 pardon me if1 before concluding these remarks1 ,i venture to make a few comments which1 though not altogether agreeable1 are made in all sincerity and in the hope of doing good4 ,the question as to how far purely technical and especially descriptive and monographic work should be done by the different stations or by the national department is one which ,i have already alluded to and upon which we shall probably hold differing opinions1 and which will be settled according to the views of the authorities at the different stations4 ,individually1 ,i have ever felt that one ostensibly engaged in applied entomology and paid by the ,state or national government to the end that he may benefit the agricultural community can be true to his trust only by largely overcoming the pleasure of entomological work having no practical bearing4 ,i would1 therefore1 draw the line at descriptive work except where it is incidental to the economic work and for the purpose of giving accuracy to the popular and economic statements4 ,this would make our work essentially biological1 for all biologic investigation would be justified1 not only because the life habits of any insect1 once ascertained1 throw light on those of species which are closely related to it1 but because we can never know when a species at present harmless may subsequently prove harmful1 and have to be classed among the species injurious to agriculture4 ,on the question of credit to their original sources of results already on record1 it is hardly necessary for me to advise1 because good sense and the consensus of opinion will in the end justify or condemn a writer according as he prove just and conscientious in this regard4 ,there is one principle that should guide every careful writer1 viz41 that in any publications whatever1 where facts or opinions are put forth1 it should always be made clear as to which are based upon the author's personal experience and which are compiled or stated upon the authority of others4 ,we should have no patience with a very common tendency to set forth facts1 even those relating to the most common and best known species1 without the indications to which ,i have referred4 ,the tendency belittles our calling and is generally misleading and confusing1 especially for bibliographic work1 and cannot be too strongly deprecated4 ,on this point there will hardly be any difference of opinion1 but ,i will allude to another question of credit upon which there prevails a good deal of loose opinion and custom4 ,it is the habit of using illustrations of other authors without any indication of their original source4 ,this is an equally vicious custom and one to be condemned1 though ,i know that some have fallen into the habit1 without appreciation of its evil effect4 ,it is1 in my judgment1 almost as blameworthy as to use the language or the facts of another without citing the authority4 ,every member of this association who has due appreciation of the time and labor and special knowledge required to produce a good and true illustration of the transformations and chief characteristics of an insect will appreciate this criticism4 ,however pardonable in fugitive newspaper articles in respect of cuts which1 from repeated use1 have become common or which have no individuality1 the habit inevitably gives a certain spurious character to more serious and official publications1 for assumption of originality1 whether intended or not1 goes with uncredited matter whether of text or figure4 ,nor is mere acknowledgment of loan or purchase to the publisher1 institution or individual who may own the block or stone what ,i refer to4 ,but that acknowledgment to the author of the figure or the work in which it first appears which is part of conscientious writing1 and often a valuable index as to the reliability of the figure4 ,it were supererogation to point out to a body of this kind the value of the most careful and thorough work in connection with life histories and habits1 often involving as it does much microscopic study of structure4 ,the officers of our institutions who control the funds1 and more or less fully our conduct1 are apt to be somewhat impatient and inappreciative of the time given to anatomic work1 and where it is given for the purpose of describing species and of synopsizing or monographing higher groups1 without reference to agriculture1 ,i am firmly of the belief that it diverts one from economic work1 but where pursued for a definite economic purpose it cannot be too careful or too thorough and ,i know of no instances better calculated to appeal to and modify the views of those inclined to belittle such structural study than ,phylloxera and ,icerya4 ,on the careful comparison of the ,european and ,american specimens of ,phylloxera vastatrix1 involving the most minute structures and details1 depended originally those important economic questions which have resulted in legislation by many different nations and the regeneration of the affected vineyards of ,europe1 of our own ,pacific coast1 and of other parts of the world by the use of ,american resistant stocks4 ,in the case of ,icerya purchasi the possibilities of success in checking it by its natural enemies hung at one time upon a question of specific difference between it and the ,icerya sacchari of ,signoret--a question of minute structure which the descriptions left unsettled and which could only be settled by the most careful structural study and the comparison of the types1 involving a trip to ,europe4 ,,conclusion4 ,i have thus touched1 gentlemen1 upon a few of the many subjects that crowd upon the mind for consideration on an occasion like this--a few gleanings from a field which is passing rich in promise and possibility4 ,it is a field that some of us have cultivated for many years and yet have only scratched the surface1 and if ,i have ventured to suggest or admonish1 it is with the feeling that my own labors in this field are ere long about to end and that ,i may not have another occasion4 ,at no time in the history of the world has there1 ,i trow1 been gathered together such a body of devoted and capable workers in applied entomology4 ,it marks an era in our calling and1 looking back at the progress of the past fifteen years1 we may well ponder the possibilities of the next fifteen4 ,they will be fruitful of grand results in proportion as we persistently and combinedly pursue the yet unsolved problems and are not tempted to the immediate presentation of separate facts1 which are so innumerable and so easily observed that their very wealth becomes an element of weakness4 ,epoch-making discoveries result only from this power of following up unswervingly any given problem1 or any fixed ideal4 ,the kerosene emulsion1 the ,cyclone nozzle1 the history of ,phylloxera vastatrix1 of ,phorodon humuli1 of ,vedalia cardinalis1 are illustrations in point1 and while we may not expect frequent results as striking or of as wide application as these1 there is no end of important problems yet to be solved and from the solution of which we may look for similar beneficial results4 ,applied entomology is often considered a sordid pursuit1 but it only becomes so when the object is sordid4 ,when pursued with unselfish enthusiasm born of the love of investigation and the delight in benefiting our fellow men1 it is inspiring1 and there are few pursuits more deservedly so1 considering the vast losses to our farmers from insect injury and the pressing need that the distressed husbandman has for every aid that can be given him4 ,our work is elevating in its sympathies for the struggles and suffering of others4 ,our standard should be high--the pursuit of knowledge for the advancement of agriculture4 ,no official entomologist should lower it by sordid aims4 ,during the recent political campaign the farmer must have been sorely puzzled to know whether his interests needed protection or not4 ,on the abstract question of tariff protection to his products we1 as entomologists1 may no more agree than do the politicians or than does the farmer himself4 ,but ours is a case of protection from injurious insects1 and upon that there can nowhere be division of opinion4 ,it is our duty to see that he gets it with as little tax for the means as possible4 99 99 99 99 99 ,,potash ,,salts4 ,footnote3 ,by ,john ,b4 ,smith1 entomologist4 ,potash as an insecticide is not entirely new1 but has never been brought out with the prominence ,i think it deserves4--,n4,j4 ,ag4 ,col4 ,exp4 ,st41 ,bulletin #ge4 ,my attention was attracted to potash salts as an insecticide1 by the casual remark of an intelligent farmer1 that washing his young pear trees with a muriate of potash solution cleared them of scales4 ,the value of this substance for insecticide purposes1 should its powers be sufficient1 struck me at once1 and ,i began investigation4 ,it was unluckily too late in the season for field experiments of the nature desired2 but it is the uniform testimony of farmers who have used either the muriate or the kainit in the cornfields1 that they have there no trouble with grubs or cut worms4 ,mr4 ,e4,b4 ,voorhees1 the senior chemist of the station1 assures me that on his father's farm the fields were badly infested1 and replanting cornhills killed by grubs or wire worms was a recognized part of the programme4 ,since using the potash salts1 however1 they have had absolutely no trouble1 and even their previously worst-infested fields show no further trace of injury4 ,the same testimony comes from others1 and ,i feel safe in recommending these salts1 preferably kainit1 to those who are troubled with cut worms or wire worms in corn4 ,,experiments4 ,a lot of wire worms 7,iulus sp47 brought in from potato hills were put into a tin can with about three inches of soil and some potato cuttings1 and the soil was thoroughly moistened with kainit1 one ounce to one pint of water4 ,next morning all the specimens were dead4 ,a check lot in another can1 moistened with water only1 were healthy and lived for some days afterward4 ,a number of cabbage maggots placed on the soil impregnated with the solution died within twelve hours4 ,to test its actual killing power1 used the solution1 one ounce kainit to one pint water1 to spray a rose bush badly infested with plant lice4 ,effect1 all the lice dead ten hours later2 the younger forms were dropping within an hour4 ,sprayed several heads of wheat with the solution1 and within three hours all the aphides infesting them were dead4 ,some experiments on hairy caterpillars resulted unsatisfactorily1 the hair serving as a perfect protection against the spray1 even from the atomizer4 ,to test its effect on the foliage1 sprayed some tender shoots of rose and grape leaves1 blossoms1 and clusters of young fruit4 ,no bad effect observable #bd hours later4 ,there was on some of the leaves a fine glaze of salt crystals1 and a decided salt taste was manifest on all4 ,muriate of potash of the same strength was tested as follows3 ,sprayed on some greenhouse camellias badly infested by mealy bugs1 it killed nearly all within three hours1 and six hours later not a living insect was found4 ,the plants were entirely uninjured by the application4 ,thoroughly sprayed some rose bushes badly infested with aphides1 and carried off some of the worst branches4 ,on these the lice were dead next morning2 but on the bushes the effect was not so satisfactory1 most of the winged forms and many mature wingless specimens were unaffected1 while the terminal shoots and very young leaves were drooping as though frosted4 ,all1 however1 recovered later4 ,the same experiment repeated on other1 hardier roses1 resulted similarly so far as the effect on the aphides was concerned1 but there was no injury to the plant4 ,used this same mixture on the caterpillars of ,orgyia leucostigma with unsatisfactory effect1 and with the same results used it on a number of other larv4 ,used on the rose leaf roller1 ,caccia rosaceana1 it was promptly effective4 ,tested for injury to plants1 it injured the foliage and flowers of wisteria1 the younger leaves of maple and grape1 and the finer kinds of roses4 ,from these few experiments kainit seems preferable to the muriate1 as acting more effectively on insects and not injuriously on plants4 ,for general use on plants it is not to be recommended4 ,it is otherwise on underground species1 where the soil will be penetrated by the salts and where the moisture evaporates but slowly1 and the salt has a longer and better chance to act4 ,the best method of application would be a broadcasting in fertilizing quantity before or during a rain1 so as to carry the material into the soil at once4 ,in cornfields infested with grubs or wire worms1 the application should be made before planting4 ,where it is to be used to reach root lice1 it should be used when the injury is beginning4 ,when strawberry beds are infested by the white grub1 the application should be made when cultivating or before setting out4 ,the potash salts have a high value as fertilizers1 and any application made will act as a stimulant as well as insecticide1 thus enabling the plants to overcome the insect injury as well as destroying the insect4 ,in speaking on this subject in ,salem county1 ,i learned from farmers present that those using potash were not troubled with the corn root louse to any extent1 and also that young peach trees have been successfully grown in old lice-infested orchards1 where previously all died1 by first treating the soil with kainit of potash4 99 99 99 99 99 ,a meteorological station has been built on ,mont ,blanc1 at an elevation of #ac1cjj feet1 under the direction of ,m4 ,vallot4 ,it required six weeks to deliver the materials4 ,the instruments are self-registering and are to be visited in summer every fifteen days if possible1 the instruments being left to register between the visits4 ,in the winter the observatory will be entirely inaccessible4 ,this is the highest scientific station in ,europe1 but is #hdg feet lower than the ,pike's ,peak station in ,colorado4 99 99 99 99 99 ,,the ,,expense ,,margin ,,in ,,life ,,insurance4 ,the principle of mutuality requires that the burden of expense in life insurance should be borne by all the members equally2 but1 even with the most careful adjustment1 the allowance usually made is considerably in excess of what is needed in the regular companies doing business on the level premium plan4 ,it is customary in these companies to add to the net premium a percentage thereof to cover the expense account4 ,this practice1 though in harmony with the commission system1 is so clearly defective and so far removed from the spirit of life insurance mathematics1 that it scarcely deserves even this passing notice4 ,it is generally understood that these corporations combine the functions of the savings bank and life insurance company1 and it is only by separating the two in our minds as far as possible that we can obtain a clear conception of the laws that should govern the apportionment of the expenses among the great variety of policies4 ,while it is a comparatively simple matter to state the amount of either the insurance or savings bank element in a single policy1 it is by no means easy1 as things go1 to classify the company's actual expenses on this basis4 ,fortunately1 we can pretty accurately determine what these amounts should be in any particular case4 ,in the first place1 there are institutions in our midst devoted solely to receiving and conserving small sums of money2 doing1 in fact1 exactly what our insurance companies are undertaking to do with the reserve and contributions thereto4 ,these savings banks are required by law to make returns to the ,state commissioner1 from whose official report we can get a very good idea of the expense attendant on doing this business4 ,confining ourselves to the city banks1 where the conditions more nearly resemble those of the insurance companies1 we find in thirty-eight combined institutions for saving in the ,state of ,massachusetts a deposit in #ahhh of #aib1agd1eff1 taken care of at an aggregate cost of #dee1chg1 or about #bd-ajj of one per cent4 ,the same ratio carried out for all the savings banks in ,massachusetts gives a trifle over #be-ajj of one per cent42 we may1 therefore1 consider of one per cent4 as expressing pretty nearly the cost of receiving1 paying out1 and investing the savings of the people4 ,we must remember in this connection that in the popular estimation1 the savings bank is an important factor in the public welfare1 and in the towns and smaller cities there are often found public spirited men willing to give their services to encourage this mode of saving2 but public sentiment has not yet given to life insurance the place which it is destined1 sooner or later1 to occupy by the side of the savings bank4 ,hence the services of able managers can only be obtained by a liberal outlay of the corporate funds4 ,a satisfactory adjustment of the matter of expenses will1 perhaps1 do more than anything else to bring about this recognition on the part of the public4 ,in the case of the savings bank it is safe to say that for double the present outlay a liberal salary could be paid to all the officers4 ,following the analogy1 we are led to infer that if this be the case in savings banks1 then of one per cent4 of the reserve should be an ample allowance for the special labor required in the purely banking portion of the business4 ,in this we have the concurrence of the late ,elizur ,wright4 ,in an essay on this subject he says3 ,the expenses of the five largest savings banks in ,boston1 in #ahfi1 did not exceed #d-aj of one per cent4 on #bh1jjj1jjj deposited in them4 ,they certainly had twice as many transactions1 in proportion to the deposits1 as any life insurance company could have with the same amount of reserve1 so that of one per cent4 on the reserve seems to be ample for all working expenses save those of maintaining the agencies and collecting the premiums4 ,this need hardly be looked upon as an admission that it costs twice as much to care for the funds of a life insurance company as for those of a savings bank4 ,a liberal expense allowance must be made at the outset1 seeing that an error in this particular cannot easily be rectified after the policy is issued4 ,the dividend1 or1 to speak more correctly1 the annual return of surplus1 will correct any overpayment on this account4 ,there is another expense which seems inevitable4 ,this is the government tax on insurance companies1 amounting in the aggregate to nearly #a_/c of one per cent4 on the reserve4 ,when we consider that these institutions are intended to encourage thrift and to relieve the community from the care of numberless widows and orphans1 it seems a clear violation of the principles of political economy to levy a tax on this business2 still1 whatever our opinion may be as to the justice or injustice of the imposition1 the tax is maintained and must be provided for4 ,consequently a further allowance of of one per cent4 must be added to the net premium to cover the same1 making a total of #a per cent4 of the reserve for banking expenses and taxes4 ,considering this point as settled for the time being1 let us proceed to investigate the insurance expenses4 ,here1 again1 we are fortunate in being able to refer to the official reports of a class of corporations doing nearly1 if not quite pure insurance4 ,the assessment societies1 outside of the fraternal and benevolent1 reporting in #ahhi to the insurance commissioner of ,massachusetts1 show outstanding risks amounting to #gcc1eae1cff4 ,losses to the amount of #g1bgj1bch were paid during the year at a cost for transacting the business of #b1djc1jec1 which includes among other items agency expenses and commissions1 which amount to about #a1bjc1jjj1 or #ag per cent4 of the cost value of the insurance actually done4 ,it would seem as if an allowance of #bj per cent4 would be a liberal one in the case of the regular companies1 which surely have as good facilities for doing business as the assessment societies4 ,as far as insurance is concerned1 there is less difference between regular and co-operative companies than is generally supposed4 ,regular companies assess each policy in advance for a year's insurance at a time1 while co-operative societies furnish insurance only from one assessment to another4 ,the difficulty in the way of collecting the assessment in the latter case would seem to be greater than in the former1 owing to the more permanent nature of the regular insurance contract4 ,in compensating agents the assessment companies naturally pay in proportion to the insurance obtained1 inasmuch as there is no other basis to go upon1 but regular companies usually pay the agent a percentage of the premium which includes a considerable trust fund over and above the assessment for actual insurance4 ,it is easily seen that by the last method the agent's compensation increases in proportion to the amount of savings bank business forced upon the company4 ,to realize how far we are from anything like a scientific1 not to say common sense basis for insurance expenses1 we have but to examine the following list1 which gives the ratios between the expenditures for general expenses in #ahhi1 and those for the extension of the business4 ,for every #ajj used in a general way1 the different companies spend for commissions and agency expenses3 #cg1 #ff1 #fg1 #gh1 #ia1 #ajf1 #aaj1 #aac1 #abj1 #adj1 #aeg1 #afa1 #agc1 #age1 #ahf1 #ahi1 #bjj1 #bjb1 #bbb1 #bfd1 #caa1 #cdf4 ,it will doubtless be said that ,i am taking a very advanced position when ,i say that in the ideal life insurance scheme there is no place for the commission system4 ,solicitors will be a necessity only so long as they are in the field1 but fifty years of life insurance has taught our community its true value and1 thanks to the modern press1 the institution it is no more likely to fall into desuetude than is ,christianity or the moral law4 ,for the convenience of bringing the company to the individual1 the latter should be willing to pay a fee4 ,the man who renders another a service or puts his superior knowledge at another's disposal should look to the party benefited for his remuneration4 ,any compensation given for such service to a go-between by a mutual company is paid by all1 and the question arises1 ,is the advantage to the company of sufficient importance to warrant the imposition of this tax upon all its members promiscuously8 ,the following1 from the ,massachusetts ,insurance ,commissioner's ,report for #ahhe1 leaves no doubt as to the convictions of the writer on this important matter3 ,the expensiveness of the life insurance policy is not because the level net premium is too high1 for the premium is absolutely just1 and the policy holder gets full value2 but the complaint justly applies to the excessive expense charge4 ,a person who wants insurance1 life or fire or other1 should be able to buy it at first cost without paying tribute of profits to middlemen4 ,to that complexion the matter will finally be brought by the force of intelligent opinion1 whatever resistance may be opposed by persons whose thrift lies in the perpetuation of the expensive system now in fashion4 ,it requires but a slight degree of prophetic vision to predict that in a very few years the companies in self defense will be obliged to change their method of compensating agents4 ,several companies have already begun the reform by grading commissions2 granting a percentage proportional to the amount of insurance likely to be done on the policy4 ,other companies have simply reduced the amount of the commission rate1 thus virtually withdrawing from active competition4 ,this will1 in a certain degree1 explain the wide variation in the figures given above1 where it is noticed that1 in five companies out of twenty-two1 the total agency expenditures amount to less than the general expenses1 while in six cases the companies spend more than double as much on the former as on the latter4 ,in either class we find representatives of the five largest companies in the country4 ,on applying the foregoing ratios to the business of the existing companies we find that1 calling the theoretical expenses #ajj1 the actual expenditures for #ahhi were as follows3 #aab4fg1 #aah4cd1 #aej4dj1 #aid4dh1 #bjh4af1 #bjh4ec1 #bbh4ff1 #bce4hi1 #bdh4dd1 #bej4gi1 #beh4cc1 #beh4eg1 #bfe4ad1 #bfg4ai1 #bfg4ib1 #bgd4dg1 #bid4ag1 #cad4if1 #cce4gj1 #cgg4id1 #faf4gj4 ,in this discouraging exhibit there is one ray of comfort4 ,the combined assets of the two companies heading the list amount to over #ajj1jjj1jjj4 ,there is no question as to their financial standing1 and both show a large increase in membership over the previous year4 ,i may also say here that it is a difficult matter to get at the actual cost of insurance in the various companies4 ,many of them1 on their own acknowledgment1 do not compute the advance cost of carrying their amount at risk1 and others1 for reasons of their own1 do not care to state the figures4 ,in cases where the correct figures were not obtainable1 ,i have assumed the cost to have been #a-a_/c per cent4 of the mean amount at risk4 ,if we should1 in our comparison1 omit the actual agency expenses and commissions1 the ratios would stand as follows3 ,where ,i would allow #ajj the companies actually used3 #dc4ag1 #ee4ij1 #fe4ba1 #gg4ba1 #hb4ci1 #hh4cd1 #ia4ii4 #ia4ih4 #ib4ai1 #id4fe1 #ig4ae4 #ii4ee4 #ii4aa4 #ajb4hf1 #aji4ce1 #abe4je1 #acc4jc1 #ada4ib1 #aie4ij1 #bjg4jf1 #bhg4gb4 ,as might be supposed1 the first two ratios are those companies before alluded to4 ,these companies might have doubled their advertising account and expended #cjj1jjj between them on agents' salaries1 and still have kept within my allowance4 ,admitting1 for the present at least1 the reasonableness of the proposed allowance for the expenses of the banking and insurance departments of the business1 we have before us the problem how to equitably adjust the burden among the great variety of policies4 ,in the first place1 there should be no policy in the company that does not contribute its proportionate share of the expense allowance during every year of its life4 ,i make a special point of this1 for at present the policies which have become paid up1 either by the payment of a single premium at the outset or by the completion of a stipulated number of payments1 contribute practically nothing to the expense account after the premium payments cease4 ,the following plan1 ,i think1 complies with all the requirements of the problem4 ,by the proposed method every policy1 at all stages of its existence1 contributes its exact share to the expense fund1 whatever its plan of payment may be4 ,let us1 as an illustration1 examine the case of a ten year endowment policy1 taken out at age #cj1 and consider it under three aspects1 first1 as paid for in advance by a single payment1 second1 as paid by five annual payments1 and third1 as paid for annually throughout the term4 ,i have used this short term endowment policy simply for convenience1 the rule applying equally to policies of longer term or to the ordinary life policy1 which is1 in fact1 an endowment policy payable at death or age #ajj4a ,footnote #a3 ,the expense allowance on a plain life policy for #a1jjj1 taken at age #cc1 would be about #e4bi2 net premium 7com4 ex4 #d per cent471 #ah4jd2 total office premium1 #bc4cc2 present rate #bd4aj4 ,taking the case of the single premium endowment policy for #a1jjj1 we find that the following sums are required1 each year to provide for the care of the reserve and to pay the government fees 7#a per cent4 of reserve73 #ast year #f4iihb #fth year #h4dacf #b;d #g4befj #gth #h4gcha #c;d #g4ebeh #hth #i4jgha #dth #g4hjhb #ith #i4dcdf #eth #h4ajci #ajth #i4hjhf ,the insurance expenses should be covered by the #bj per cent4 allowance given below3 #ast year 4#ddbb #fth year 4#beff #b;d 4#dajj #gth 4#bjgf #c;d 4#cgfb #hth 4#aeef #dth 4#cdjb #ith 4#jihh #eth 4#biif #ajth 4#jcdd ,consequently the total contribution required from this policy each year is3 #ast year #g4ddjd #fth year #h4fgjb #b;d #g4fffj #gth #h4ideg #c;d #g4ijbj #hth #i4bccg #dth #h4adhd #ith #i4eccd #eth #h4djcd #ajth #i4hdcj ,the present value of all these contributions is found to be1 at #d per cent4 interest1 #ga4fcid2 in other words1 this sum paid at the outset1 provides a fund from which we may deduct the current expenses of each year in advance1 and by accumulating the balance at the assumed rate of interest from year to year1 we shall have enough to pay the anticipated expenses1 leaving nothing over4 ,in the above case the sums in hand at the beginning of the year are as follows3 #ast year #ga4cfid #fth year #db4fiha #b;d #ff4gffi #gth #ce4chij #c;d #fa4dfej #hth #bg4ejji #dth #ee4gjee #ith #ah4iigi #eth #di4deid #ajth #i4hdcj ,we find a somewhat different condition existing during the first years of a #e-year endowment policy4 ,as there is more insurance and less banking1 the requirements are as follows3 ---------------------------------------- ---------- #a ,p4 ,ct4 #bj ,p4 ,ct4 on on ,total4 ,initial ,reserve4 ,cost4 ,fund4 ---------------------------------------- ---------- #ast year #a4ejch #a4begb #b4gfaj #ab4igfi #b;d #c4jdjf #a4jbaf #d4jfbb #bc4fjae #c;d #d4fejc 4#gheb #e4dcee #cc4bigi #dth #f4ccfg 4#ecgh #f4hgde #da4iech #eth #h4ajci 4#biif #h4djce #di4deid #fth #h4dacf 4#beff #h4fgjb #db4fiha #gth #h4gcha 4#bjgf #h4ibeg #ce4chij #hth #i4jgha 4#aeef #i4bccg #bg4ejji #ith #i4dcdf 4#jihh #i4eccd #ah4iigi #ajth #i4hjhf 4#jcdd #i4hdcj #i4hdcj ---------------------------------------- ---------- ,as the premium payments extend over only five years1 the expense contributions must all be paid during that time and are most conveniently made by a uniform addition to the net premium4 ,the present value of the amounts in column #c is #fj4jhai1 and the equivalent annuity for five years is #ab4igfi4 ,this amount1 received for five consecutive years1 will put the company in funds to pay current expenses and leave a reserve of #db4fiha at the beginning of the sixth year1 which1 as we have seen in the analysis of the single-premium policy1 is the sum required for future expenses on the paid up basis4 ,in like manner we find that the #aj-year annuity equivalent to the present value of the annual contributions in the case of an annual-payment policy is #e4ecd1 thus3 ---------------------------------------- ---------- #a ,p4 ,ct4 #bj ,p4 ,ct4 on on ,total4 ,initial ,reserve4 ,cost4 ,fund4 ---------------------------------------- ---------- #ast year 4#hbcd #a4cead #b4agdh #e4ecdj #b;d #a4fdgc #a4bdgh #b4hiea #i4jbge #c;d #b4ejif #a4achh #c4fdhd #aa4iaaf #dth #c4dabd #a4jbaj #d4dccd #ad4abgg #eth #d4cegb 4#hiaf #e4bdhh #ae4fafa #fth #e4cdgi 4#gecd #f4ajac #af4cafj #gth #f4chec 4#eiff #f4ihai #af4aegb #hth #g4dgbf 4#dbgj #g4hiif #ae4jgfc #ith #h4fabg 4#bdah #h4hede #ab4iigg #ajth #i4hjhf 4#jcdd #i4hdcj #i4hdcj ---------------------------------------- ---------- ,the present value of the ten yearly expense items given in the total column above is #df4fhab1 which is equal to a ten-year annuity of #e4ecd4 ,the several premiums stand now as follows3 ,,endowment3 #a1jjj1 ,,age #cj1 ,,payable ,,at ,,death ,,or #dj ,net ,prem4#b ,margin4 ,total4 ,at single premium4 #fhg4bbh #ga4fcid #geh4hfgd ,at five premiums4 #aej4fae #ab4igfi #afc4eici ,at annual premiums4 #hd4agb #e4ecdj #hi4gjfj ,footnote #b3 ,thirty ,american offices4 ,discount from middle of year1 ,vx- or 7,m x #a4jaifa7 _/ ,dx4 ,by the actuaries' rate we have1 with the customary loading for expense3 ,single premium3 #gba4ff 7loaded1 #cd4cf74 ,five premiums1 #ahh4gj 7loaded #cg4gh74 ,annual premium1 #aje4fe 7loaded #ba4aa74 ,admitting the correctness of the new method1 we must conclude that the present single premium is not sufficiently loaded to cover its own expenses1 while the annual payment policy pays more than its just share4 ,a prominent and thoroughly informed life insurance president says in this connection3 ,many of the policies1 particularly the short term endowments1 are charged with too high a percentage of expenses to prove a good investment at maturity or profitable to the insured in case of surrender4 ,this is not to be wondered at when the applicant for a #aj-year endowment policy sees at a glance that he must pay1 in the gross1 more than is returned unless he should die in the interim1 in which case a plain life or term policy would have answered the purpose4 ,under the new system of assessing expenses one form is as desirable as another1 from the standpoint of the insured or the company4 ,the new premium for the #aj-year endowment policy1 #hi4ga1 commends itself at once to the applicant1 who can easily see that his total outlay must fall short of the amount ultimately to be realized1 of course1 disregarding interest and probable dividends in both cases4 ,in discounting the future expense contributions ,i have not taken the chances of dying into account4 ,hence the expense reserve in any instance applies only to that individual case1 and1 in the event of death or surrender before the maturity of the policy1 the amount of the expense fund not used would naturally revert to the insured4 ,the scheme of expense assessment outlined above will doubtless be pronounced impracticable by the majority of insurance men4 ,such a far reaching reform is too much to hope for1 at least in the immediate future4 ,no well informed life insurance expert will deny that there are opportunities for improvement in the business1 but to graft new methods on old companies is a hopeless undertaking4 ,it is well1 however1 to have new methods well matured in advance of the public demand1 and ,i feel convinced that the ideas here set forth are in the line of the reform which1 before long1 must be instituted by the companies if they would retain the confidence and patronage of the community4 ,doubtless many insurance presidents could tell of suggestions which have impressed them favorably and which they would gladly have adopted were it not for the injustice done thereby to older members and the changes necessary to bring existing contracts into conformity with the new system4 ,similar objections may be urged against the ideas here advanced1 and ,i must confess ,i hardly see a way by which the present suggestions can be utilized by existing companies4 ,we can only hope that sooner or later some of the new theories may be practically tested4 ,meanwhile the companies at present in the field are doing a great work for the good of humanity1 even though their methods may be1 in some particulars1 more practical than scientific4 ,winchester1 ,mass4 ,,frank ,j4 ,,wills4 99 99 99 99 99 ,,the ,,flood ,,at ,,karlsbad4 ,during the flood which occurred in ,germany and ,bohemia1 the last week of ,november1 ,karlsbad was especially unfortunate2 it suffered such an inundation as had never before been known in the ,sprudelstadt4 ,on the evening of ,november #bc1 the ,tepl was very much swollen by the rain1 which had continued for several days1 but it was supposed that there was no danger of a flood1 as the bed of the river had been put in proper condition4 ,during the forenoon of ,november #bd1 the water suddenly began to rise with such astonishing rapidity that within half an hour all the lower streets were like turbulent rivers and the ,alte and ,neue ,wiese were transformed into a lake4 ,the stores on the ,alte ,wiese were under water to the roofs1 and the proprietors1 who were trying to save their goods1 were surprised by the water and had to take refuge in the trees4 ,they were rescued by having ropes thrown to them1 and during this work a catastrophe occurred which was a great misfortune to all classes of citizens4 ,the beloved burgermeister of ,karlsbad1 ,dr4 ,rudolf ,knoll1 who had just recovered from a severe illness1 was1 with others1 directing the work from the balcony of one of the houses1 when a rope by which a man was being drawn through the water broke1 and the man was carried off by the waves4 ,the fright and excitement of the scene gave the burgermeister a shock which caused his instant death1 but the man who was in danger was brought safely out of the water4 ,the water was #i ft4 in ,marienbaderstrasse1 the ,marktplatz1 ,muhlbadgasse1 the ,sprudelgasse1 ,kreuzgasse1 ,kaiserstrasse1 and ,egerstrasse1 and flooded the quay1 causing great destruction4 ,all places of business were flooded1 the doors and iron shutters were pushed in by the force of the water and the goods were carried away or ruined4 ,the house called ,zum ,kaffeebaum was undermined and part of it fell to the ground2 the same fate was feared for other buildings4 ,the ,sophien and ,curhaus bridges were carried away4 ,other bridges were greatly damaged1 and the masonry along the banks of the river was partially destroyed4 ,the ,sprudelgasse was completely washed out1 and the condition of the ,muhlbadgasse was almost as bad4 ,the fire department with its apparatus had great difficulty in saving the inhabitants and guests1 as there were very few boats or pontoons at their command1 and the soldiers 7,pionniere7 from ,prague and the firemen from the neighboring towns did not arrive until evening4 ,fortunately the water began to fall in the night1 and the next day it had gone down so that it left its terrible work visible4 ,the ,sprudel and the mineral springs were not injured1 but1 on the other hand1 the water pipes of the bathing establishments and the gas pipes were completely destroyed4--,illustrirte ,zeitung4 99 99 99 99 99 ,,theatrical ,,water ,,plays4 ,in one of the plays at ,hengler's ,circus in ,london a water scene is introduced1 for which purpose the main ring is flooded with water in a manner which is both striking and interesting4 ,illustration3 ,,flooding ,a ,,circus ,,ring4 ,the ring is entirely lined with stout macintosh sheeting1 and into this1 from two large conduits4 #bc1jjj gallons of water are poured1 the tank being filled to a depth of some #b ft4 in the remarkably short time of #ce seconds4 ,a steamboat and other small craft are then launched and the adventures of the heroine then proceed4 ,she falls overboard1 we believe1 but is saved after desperate and amusing struggles4 ,our engravings1 which are from the ,graphic1 illustrate the mode of filling the ring with water1 and the steamboat launch4 ,illustration3 ,a ,,theatrical ,,steamboat4 99 99 99 99 99 ,,science ,,in ,,the ,,theater4 ,in the pretty little hall of the ,boulevard des ,italiens1 at ,paris1 a striking exhibition of simulated hypnotism is given every evening4 ,this entertainment1 which has met with much success1 was devised by ,mr4 ,melies1 director of the establishment1 which was founded many years ago by the celebrated prestidigitator whose popular name 7,robert ,houdin7 it still bears4 ,this performance carries instruction with it1 for it shows how easily the most surprising phenomena of the pathologic state can be imitated4 ,to this effect1 several exhibitions are given every evening4 ,mr4 ,harmington1 a convinced disciple of ,mesmer1 asks for a subject1 and finds one in the hall4 ,a young artist named ,marius presents himself4 ,mr4 ,harmington makes him perform all sorts of extravagant acts1 accompanied with a continuous round of pantomimes that are rendered the more striking by the supposed state of somnipathy of the subject4 ,at the moment at which ,marius is finishing his most extraordinary exercises1 a policeman suddenly breaks in upon the stage in order to execute the recent orders relative to hypnotism4 ,but he himself is subjugated by ,mr4 ,harmington and thrown down by the vibrations of which the encephalus of this terrible magnetizer is the center4 ,when the curtain falls1 the representative of authority is struggling against the catalepsy that is overcoming him4 ,all the phenomena of induced sleep are successively simulated with much naturalness by ,mr4 ,jules ,david1 who plays the part of ,marius in this pleasing little performance4 ,at a certain moment1 after skillfully simulated passes made by the magnetizer1 ,mr4 ,david suddenly becomes as rigid as a stick of wood1 and falls in pivoting on his heels 7,fig4 #a74 ,did not ,mr4 ,harmington run to his assistance1 he would inevitably crack his skull upon the floor1 but the magnetizer stands just behind him in order to receive him in his arms4 ,then he lifts him1 and places him upon two chairs just as he would do with a simple board4 ,he places the head of the subject upon the seat of one of the chairs and the heels upon that of the other4 ,mr4 ,david then remains in a state of perfect immobility4 ,not a muscle is seen to relax1 and not a motion betrays the persistence of life in him4 ,the simulation is perfect4 ,illustration3 ,,fig4 #a4--;,,cataleptic ,,rigidity4 ,in order to complete the astonishment of the spectators1 ,mr4 ,harmington seats himself triumphantly upon the abdomen of the subject and slowly raises his feet and holds them suspended in the air to show that it is the subject only that supports him1 without the need of any other point of support than the two chairs 7,fig4 #b74 ,illustration3 ,,fig4 #b4--;,,experiment ,,on ,,the ,,same ,,subject4 ,usually1 there are plenty of persons ingenuous enough to think that ,mr4 ,david is actually in a cataleptic sleep1 one of the characters of which is cadaveric rigidity4 ,as ,mr4 ,david's neck is entirely bare1 it is not possible to suppose that the simulator of catalepsy wears an iron corset concealed beneath his clothing4 ,he has performed a feat of strength and skill rendered easy by the exercise that he has given to the muscles occupying the collici of his vertebral column4 ,this part of the muscular system is greatly developed in the weakest and least hardy persons4 ,in fact1 in order that man may keep a vertical position and execute an infinite multitude of motions in which stability is involved1 nature has had to give him a large number of different organs4 ,the muscles of the back are arranged upon several superposed layers1 the vertebral column is doubly recurved in order that it may have more strength1 and1 finally1 rachidion nerves issue from each vertebra in order to regulate the contraction of each muscular fasciculus according to the requirements of equilibrium4 ,the trick is so easy that we have seen youths belonging to the ,ligue d',education ,physique immediately imitate ,mr4 ,david after seeing him operate but once4 ,for the sake of those who would like to perform it1 we shall add that ,mr4 ,david takes care to bend his body in the form of an arch in such a way that the convexity shall be beneath4 ,as ,mr4 ,harmington never fails to place himself in the center of the line that joins ,mr4 ,david's head and heels1 his weight is divided into two parts1 that is to say1 #hh pounds on each side of the point of support4 ,the result is that the stress necessary is less than that of a strong man of the ,halle lifting a bag of wheat to his shoulder or of an athlete supporting a human pyramid4 ,the force of contraction of the muscular fibers brought into play in this experiment is much greater than is commonly believed4 ,in his lectures on physiology1 ,milne-,edwards cites some facts that prove that it may exceed #fjj pounds per square inch of section4 ,illustration3 ,,fig4 #c4--,,the ,,perforate ,,arm4 ,the experiment on cadaveric rigidity is followed by others in insensibility4 ,mr4 ,david1 without wincing1 allows a poignard to be thrust into his arm1 which ,mr4 ,harmington has previously cataleptized 7,fig4 #c74 ,this trick is performed by means of a blade divided into two parts that are connected by a semicircle4 ,this process is well known to prestidigitators1 but it might be executed in a genuine manner4 ,in fact1 on replacing the poignard by one of the gold needles used by physicians for acupuncture1 it would be possible to dispense with prestidigitation4 ,under such conditions it is possible to transpierce a person's arm4 ,the pain is supportable1 and consists in the sensation of a prick produced in the passage of the needle through the skin4 ,as for the muscular flesh1 that is of itself perfectly insensible4 ,the needle1 upon the necessary antiseptic precautions being taken1 may traverse the veins and arteries with impunity1 provided that it is not allowed to remain long enough to bring about the formation of a clot of coagulated blood 7,fig4 #d74 ,illustration3 ,,fig4 #d4--;,,an ,,arm ,,transpierced ,,by ,a ,,needle4 ,we think it of interest to add that it is necessary that the experiment be performed by a practitioner if one desires to demonstrate upon himself a very curious physiological fact that has been known from the remotest antiquity4 ,it has been employed for several thousand years in ,chinese medicine1 for opening a passage for the bad spirits that produce diseases4 ,for some years past a much more serious use has been made of it in ,european medicine for introducing electric currents into the interior of the organism4 ,in this case the perimeter of the needle is insulated1 and the electricity flows into the organism through the point4 ,we have several times had these operations performed upon ourselves1 and this permits us to assert that the above mentioned facts are absolutely true4--,la ,nature4 99 99 99 99 99 ,,newer ,,physiology ,,and ,,pathology4 ,by ,prof4 ,,samuel ,,bell1 ,m4,d4 ,physiology has for many decades been a science founded on experiment1 and pathology has been rapidly pressing forward in the same direction4 ,to read the accounts of how certain conclusions have been arrived at in the laboratory1 by ingenious devices and by skillful manipulations1 is as fascinating as any tale of adventure4 ,when the microscope began its work1 how discouraging was the vastness and complexity of the discoveries which it brought to light2 how many years has it been diligently used1 and how uncertain are we still about many of its revelations6 ,but what a happy conjecture of man1 and as proper environment takes place we may reach better results6 ,let me give an illustration3 ,some thirty years ago1 ,virchow began his studies and lectures upon cellular pathology4 ,the enthusiasm which he awakened spread over the whole medical world4 ,the wonderful attention to detail1 the broad philosophy which signalized his observations1 were alike remarkable4 ,his class room was packed with students from every country1 who thought it no hardship to struggle for a seat at eight o'clock in the morning4 ,with his blackboard behind him and specimens of pathology before him1 and microscopes coursing upon railway tracks around the tables which filled the room1 he was the embodiment of the teacher2 his highest honor was as discoverer4 ,the life and importance of the cell1 both in health and disease1 it has been his work to discover and to teach4 ,the point of view from which he has classified tumors is founded on this basis1 and remains the accepted method4 ,the light which he cast upon the nature of inflammation has not yet been obscured1 and while other phenomena appear1 the multiplication of cells and nuclei and the formation of connective tissue in the process of inflammation will always call to mind his labors4 ,to one of ,virchow's pupils1 ,prof4 ,recklinghausen1 we chiefly owe our knowledge of the phenomena of diapedesis as a part of the inflammatory activity4 ,how incredible it seems that masses of living matter can make their way through the walls of blood vessels which do not rupture and which have no visible apertures6 ,virchow fixed his attention upon the forms and activities of the cells1 their multiplication and degradation1 and how they build up tissues1 both healthy and morbid4 ,to another matter with which1 both literally and metaphorically1 the air is filled1 we must also make allusion4 ,the existence of micro-organisms in countless numbers is no new fact1 but the influence they may exert over living tissues has only lately become the subject of earnest attention4 ,so long as they were not known to have any practical bearing upon human welfare1 they interested almost nobody1 but when1 however1 it was shown that putrefaction of meat is due to the agency of the bacterium termo1 and the decomposition of albumen to the bacillus subtilis2 when anthrax in cattle and sheep was found to depend on the bacillus anthracis1 and that in human beings it caused malignant pustules2 when suppuration of wounds was found to be associated with micrococci2 and when it was announced that by a process of inoculation cattle could be protected against anthrax1 and that by carbolic spray and other well known precautions the suppuration of wounds could be prevented--all the world lent its ears and investigation at once began4 ,because labors in bacteriology promised to be fruitful in practical results1 the workers speedily became innumerable1 and we are accumulating a wondrous store of facts4 ,how long now is the list of diseases in which germs make their appearance--in pneumonia1 in endocarditis1 in erysipelas1 in pymia1 in tuberculosis1 and so on and so on4 ,one of the most striking illustrations is the gonococcus of gonorrhoea1 whose presence in and around gives to the pus cells their virulent properties1 and when transferred to the eye works such lamentable mischief4 ,without their existence the inoculation of pus in the healthy eye is harmless2 pus bearing the gonococci excites the most intense inflammation4 ,similar suppurative action in the cornea is often caused by infection of cocci4 ,the proof of causation may be found in the fact that the most effective cure now practiced for such suppuration is to sterilize them by the actual cautery4 ,rosenbach says that he knows six distinct microbes which are capable of exciting suppuration in man4 ,their activity may be productive of a poison1 or putrefactive alkaloid1 which is absorbed4 ,there are at present two prominent theories in regard to the infections which produce disease4 ,the first is based upon chemical processes1 the second upon the multiplication of living organisms4 ,the chemical theory maintains that after the infectious element has been received into the body it acts as a ferment1 and gives rise to certain morbid processes1 upon the principle of catalysis4 ,the theory of organisms1 or the germ theory1 maintains that the infectious elements are living organisms1 which1 being received into the system1 are reproduced indefinitely1 and excite morbid processes which are characteristic of certain types of disease4 ,this latter theory so readily explains many of the facts connected with the development and reproduction of infectious diseases1 that it has been unqualifiedly adopted by a large number of investigators4 ,the proofs of this theory had not1 however1 advanced beyond the demonstrations of the presence of certain forms of bacteria in the pathological changes of a very limited number of infectious diseases1 until ,february1 #ahhb1 when ,koch announced his discovery of the tubercle bacillus1 since which time nearly every disease has its supposed microbe1 and the race is1 indeed1 swift in which the would-be discoverers press forward with new germs for public favor4 ,the term bacteria or microbe refers to particles of matter1 microscopic in size1 which belong to the vegetable kingdom1 where they are known as fungi4 ,if we examine a drop of stagnant water under the microscope1 amplifying say four hundred diameters1 we see it loaded with minute bodies1 some mere points1 others slightly elongated into rods1 all actively in motion and in various positions1 a countless confusion4 ,if evaporation now takes place1 all is still4 ,if we now apply moisture1 the dried-up granules will show activity1 as though they had not been disturbed4 ,all these different organisms have become familiar to us under the generic term bacteria1 which is a very unfortunate application1 as it really applies to only a single class of fungi4 ,cohn calls them schizomycetes1 and makes the following classifications3 #a4 ,sphero-bacteria1 or microbes4 #b4 ,micro-bacteria1 or bacteria4 #c4 ,desmo-bacteria1 or bacilli4 #d4 ,spiroteria1 or spirill4 ,the spiro-bacteria1 or micrococci1 are the simplest of the fungi1 and appear as minute organisms of spherical form4 ,they multiply by fission1 a single coccus forming two1 these two producing four1 and so on4 ,they present a variety of appearances under the microscope4 ,from single isolated specimens 7which under the highest magnifying power present nothing beyond minute points7 you will observe them in pairs1 again in fours1 or in clusters of hundreds 7forming zoglea7 and still adhering together1 forming chains4 ,when a given specimen is about to divide1 it is seen to elongate slightly1 then a constriction is formed1 which deepens until complete fission ensues4 ,micrococci possess no visible structure4 ,they consist of a minute droplet of protoplasm 7mycroprotein7 surrounded by a delicate cell membrane4 ,certain forms are embedded in a capsule 7diameter #j4jjjh to #j4jjja millimeter74 ,these little organisms1 when observed in a fluid like blood1 sputum1 etc41 are found to present very active movements1 although provided with no organs of locomotion4 ,this ,brownian motion is possessed by almost every minute particle of matter1 organic and inorganic1 and is not due to any inherent power of the individual4 ,they are almost omnipresent1 abounding in the air1 the earth1 the water1 are always found in millions where moist organic matter is undergoing decomposition1 and are associated with the processes of fermentation--in fact1 they are essential to it4 ,the souring of milk succeeds the multiplication of these germs4 ,certain varieties are pigmented1 and we observe colonies of chromogenic cocci multiplying upon slices of boiled potato1 eggs1 etc41 presenting all the colors of the rainbow4 ,all of these germs are not the cause of disease4 ,certain species1 however 7termed pathogenic71 are always associated with certain diseased conditions4 ,the bacteria-termo--micro-bacteria--are slightly elongated1 and inasmuch as they multiply by division1 frequently appear coupled together1 linked in pairs1 and in chains4 ,they are generally found in putrefying liquids1 especially infusions of vegetable matter4 ,they possess mobility to a remarkable degree4 ,observing a field of bacteria-termo under the microscope1 they may be seen actively engaged in twining and twisting4 ,a flagellum has been demonstrated as attached to one or both extremities4 ,this is too minute to be generally resolved1 even if it is a common appendage4 ,desmo-bacteria 7or bacilli7 are rod-like organisms1 occurring of various lengths and different thicknesses4 ,in a slide of the bacillus of tuberculosis and anthrax1 we notice at intervals dots which represent the spores from which1 as the rods break up1 future bacilli are developed4 ,then we have spiro-bacteria1 the spirilla and the spirochet2 the former having short open spirals1 the latter long and closely wound spirals4 ,the spirillum1 volutans is often found in drinking water1 and in common with some other specimens of this class is provided with flagell1 sometimes at both extremities1 which furnish the means of rapid locomotion4 ,the spiro-bacteria multiply by spores1 although little is at present known of their life history4 ,they frequently are attached together at their extremities1 forming zigzag chains4 ,we have seen that bacteria differ greatly in appearance from the elongated dot of the bacterium proper1 to the elongated rod or cylinder of the bacillus1 and the long spirals of spiro-bacteria4 ,it is unfortunate that they are not sufficiently constant in habit to always attach themselves to one or the other of these genera4 ,the micrococcus has a habit of elongating at times until it is impossible to recognize him except as a bacterium2 while bacilli1 again1 break up until their particles exactly resemble micrococci4 ,bacteria cannot exist without water2 certain forms require oxygen1 while others thrive equally well without it2 some thrive in solution of simple salts1 while others require albuminoid material4 ,bacteriology1 with its relation to the science of medicine1 is of importance to every investigating physician2 it covers our knowledge of the relation of these minute organisms to the tiology of disease4 ,what has been gained as to practical application in the treatment of disease8 ,this question is not infrequently asked in a sneering manner4 ,we can1 in reply1 say that the results are not all in the future4 ,it is encouraging that results have been attained which have had a very important practical bearing1 and that these complaints come generally from individuals least acquainted with scientific investigations in bacteriology4 ,in the study of the relation of a given bacterium to a certain disease1 it becomes necessary to attend carefully to three different operations3 ,first1 the organism supposed to cause the disease must be found and isolated4 ,second1 it must be cultivated through several generations in order that absolute purity may be secured4 ,lastly1 the germ must be again introduced into a healthy living being4 ,if the preceding steps be carried out1 and the original disease be communicated by inoculation1 and the germs be again found in the diseased body1 we have no alternative2 we must conclude that we have ascertained the cause of the disease4 ,the importance of being familiar with the tiology of the disease before we can expect to combat it with any well-grounded hope of success is evident4 ,if the sputum of a phthisical patient be submitted to the skilled microscopist1 he is nearly always able to demonstrate bacilli1 but this goes for very little4 ,because bacilli are found in phthisis1 it is no more certain that they are the cause of phthisis than it is certain that cheese mites are the cause of cheese4 ,well1 suppose we were to inject sputum from a phthisical person into the lower animal and tuberculosis follows1 and then announce to the profession that we have demonstrated the relation of the cause and effect between bacilli and phthisis8 ,why we would start such an uproar of objections as would speedily convince us that there was much work yet in the domain of bacteriology4 ,the scientific investigators would say you have injected with the sputum into the blood of your unfortunate patient1 pus1 morphological elements1 and perhaps half a dozen other forms of bacteria1 any one of which is just as likely to produce the disease as the bacillus you have selected4 ,the first important step is1 first isolate your bacillus4 ,if ,i were to take a glass plate1 one side of which is coated with a thick solution of peptonized gelatin1 and allow the water to collect1 the gelatinous matter will become solid4 ,if now1 with a wire dipped in some tuberculous matter1 ,i draw a line along the gelatin1 ,i have deposited at intervals along this line1 specimens of tubercle bacilli4 ,if this plate be now kept at a proper temperature1 after a few days1 wherever the bacilli have been caught1 a grayish spot will appear1 which1 easily seen with the naked eye1 gradually spreads and becomes larger4 ,these spots are colonies containing thousands of bacilli4 ,let us return to our gelatin plate4 ,we find a spot which answers to the description of a colony of tubercle bacilli4 ,we now take a minute particle from this colony on a wire and convey it to the surface of some hardened blood serum in a test tube4 ,we plug the tube so that no air germs may drop in1 and place it in an incubator at the proper temperature4 ,after several days1 if no contamination be present1 a colony of bacilli will appear around the spot where we sowed the spores4 ,let us repeat the process4 ,take a particle from this colony1 and transfer it to another tube4 ,this is our second culture4 ,this must be repeated until we are satisfied that we have secured a pure culture4 ,if this be carried to the twenty-fifth generation1 we may be assured that there remains no pus1 no ptomaines1 nothing but the desired bacilli4 ,it is a proper material now for inoculation1 and if we inoculate some of the lower animals1 for instance the monkey1 we produce a disease identical with phthisis pulmpnalis4 ,bacteria also afford peculiar chemical reactions4 ,for example1 nitric acid will discharge all the color from all bacilli artificially dyed with anilin1 except those of tubercle and anthrax4 ,one species is stained readily with a dye that leaves another unaltered4 ,thus we are enabled in the laboratory to determine whether the bacilli found in sputum1 for example1 are from tubercle or are the bacteria of decomposition4 ,from what ,i have said of the tubercle bacillus1 it would seem thoroughly demonstrated that it is the cause of tubercle in these animals4 ,but we must walk cautiously here4 ,these are not human beings1 who know that like results would follow their inoculation4 ,the animals used by ,koch are animals very subject to tubercle4 ,we must1 from the very nature of our environment1 be constantly inhaling these germs as we pass through the wards of our hospitals2 yes1 they are floating in the air of our streets and dwellings4 ,it becomes necessary then for us to inquire3 ,if bacteria cause disease1 in what manner do they produce it8 ,the healthy organism is always beset with a multitude of non-pathogenic bacteria4 ,they occupy the natural cavities1 especially the alimentary canal4 ,they feed on the substances lying in their neighborhood1 whether brought into the body or secreted by the tissues4 ,in so doing they set up chemical changes in their substances4 ,where the organs are acting normally these fungi work no mischief4 ,the products of decomposition thus set up are harmless1 or are conveyed out of the body before they begin to be active4 ,if bacteria develop to an inordinate degree1 if the contents of organs are not frequently discharged1 fermentative processes may be set up1 which result in disease4 ,bacteria must always multiply and exist at the expense of the body which they infest1 and the more weakened the vital forces become1 the more favorable is the soil for their development4 ,septicmia is caused by the absorption of the products of putrefaction1 induced before bacteria can multiply inside or outside the body4 ,bacteria must find a congenial soil4 ,the so-called cholera bacillus must gain access to the intestinal tract before it finds conditions suitable to colonization4 ,it does not seem to multiply in the stomach or in the blood1 but once injected into the duodenum develops with astonishing rapidity1 and the delicate epithelial cells of the villi become swollen1 soften and break down1 exposing the mucosa4 ,it has been shown that bouillon in which ,loeffler's diphtheria bacillus has grown1 and which has been passed through unglazed porcelain filters1 shows the presence of a poison which is capable of producing the same results upon inoculation as the pure culture of the bacillus itself4 ,zarniko1 working upon the same organism1 obtained a number of positive results that led him to declare this bacillus is the cause of epidemic diphtheria1 in spite of many assertions to the contrary4 ,chantmesse and ,widal record the results of their work as to what will most easily and effectively destroy the bacillus of diphtheria4 ,the only three substances that actually checked and destroyed its vitality were phenic acid 7#e per cent471 camphor 7#bj per cent471 olive oil 7#be per cent471 in combination4 ,for the last ,i substitute glycerine1 because this allows the mixture to penetrate farther into the mucous membrane than oil1 the latter favoring a tendency to pass over the surface4 ,this mixture when heated separates into two layers1 the upper one viscid and forming a sort of glycerol1 the lower clear4 ,the latter will completely sterilize a thread dipped in a pure culture of the diphtheria bacillus4 ,corrosive sublimate was not examined because in strong enough doses it would be dangerous and in weaker ones it would be useless4 ,the facts obtained in regards to the streptococcus of erysipelas are reported as follows3 ,that both chemical and experimental evidence teach the extreme ease of a renewed attack of the disease2 that it is possible to kill guinea pigs by an intoxication when they are immune to an inoculation of the culture in ordinary quantities4 ,and this latter fact should warn experimenters trying to obtain immunity in man by the inoculation of non-pathogenic bacteria1 because the same results may be reached4 ,a new theory in regard to fevers and the relation of micro-organisms is suggested by ,roussy1 viz43 ,that it is a fermentation produced by a diastase or soluble ferment found in all micro-organisms and cells1 and which they use in attacking and transforming matter1 either inside their substance or without it4 ,the resemblance of the malaria parasite to that of recurrent fever is noted in the work of ,sacharoff4 ,he states that there exists in the blood of those suffering from recurrent fever a hmatozoon1 which is most prominent after the fever has begun to fall1 when it is of enormous proportions1 twenty or more diameters of a red blood corpuscle1 although smaller ones may still be found4 ,the parasite consists of a delicate amoeboid body containing a multitude of dark1 round1 uniform1 sharply outlined1 movable granules4 ,besides these1 the protoplasm contains a generally grayish homogeneous nucleus as large as one or two red blood corpuscles4 ,the protoplasm sends out pseudopodia 7with granules71 which sometimes separate and appear as small delicate pieces of protoplasm4 ,they vary in size1 and are often swallowed by the red blood corpuscles in which they grow1 and finally develop into the above mentioned amoeboid bodies4 ,prof4 ,j4 ,lewis ,smith has made a great many autopsies of children dead from cholera infantum1 and almost invariably found the stomach and liver in a comparatively healthy condition4 ,ganghen1 who has given this subject considerable study1 denies the existence of any specific germ in the summer diarrhea of infants1 but claims to have found three different germs in the intestines of children suffering from cholera infantum1 each producing a chemical poison which is capable of producing vomiting1 purging1 and even death4 ,a great variety of germs are found in drinking water1 and no doubt countless numbers are taken into the digestive tract1 and the principal reason why pathological conditions do not occur more frequently is on account of the germicidal qualities of the gastric juice4 ,the comma bacillus of ,koch1 and the typhoid fever germ of ,eberth1 are especially destroyed in normal gastric juice4 ,when the germs are very numerous1 they run the gauntlet of the stomach 7as the gastric juice is secreted only during digestion72 and once in the alkaline intestinal canal they are capable of setting up disease1 other conditions contributing--ill health1 deranged digestion1 etc4 ,mittnam has made a study of bacteria beneath the nails1 and reports1 after examining persons following different occupations1 having found numerous varieties of micro-organisms2 which are interesting from a scientific standpoint relative to the importance of thoroughly cleansing the hands before undertaking any surgical procedure4 ,he found1 out of twenty-five experiments1 #gh varieties of bacteria1 of which #cf were classed as micrococci1 #ba diplococci1 #ah rods1 #c sarcin1 and #a yeast4 ,cooks1 barbers1 waiters1 etc41 were examined4 ,the blood1 defibrinated and freshly drawn1 has marked germicidal action2 for bacteria its action is decidedly deadly1 even hours after it has been drawn from the body4 ,especially were anti-germic qualities noticed upon pathogenic bacteria4 ,buchner put the bacilli of anthrax in a quantity of blood1 and in two hours the number was reduced from #d1hjj to #ef1 and in three hours only #c living bacteria remained4 ,other bacteria were experimented upon in blood with similar results1 but the destruction of the organism from putrefaction was much less marked1 and on some varieties the blood had little or no action4 ,it is not the object of these remarks to even give a rsum of the status prsens of bacteriology1 but simply to stimulate thought in that direction4 ,the claims of some of the ultra-bacteriologists may never be realized1 but enough has been accomplished to revolutionize the treatment of certain diseases1 and the observing student will do well to keep his eye on the microbe1 as it seems from the latest investigations that its star is in the ascendant4 ,and who can prognosticate but that in the next decade an entire revolution in the tiology and treatment of many diseases may take place8 ,detroit1 ,mich4 99 99 99 99 99 ,,the ,,composition ,,of ,,koch',s ,,lymph4 ,,what ,,professor ,,koch ,,says ,,it ,,is1 ,,and ,,what ,,it ,,can ,,do4 7,by ,cable to the ,medical ,record47 ,,berlin1 ,january #ae1 #ahia4 ,the curiosity to know the composition of the famous lymph has been gratified by the publication to-day of an article by ,professor ,koch on the subject4 ,in the following1 as will be seen1 he reaffirms his original convictions and acknowledges the valuable assistance he has received from those who have used his fluid1 and thus helped him in the accumulation of experience4 ,professor ,koch says3 ,two months ago ,i published the results of my experiments with the new remedy for tuberculosis1 since which time many physicians who received the preparation have been enabled to become acquainted with its properties through their own experiments4 ,so far as ,i have been able to review the statements published and the communications received by letter1 my predictions have been fully and completely confirmed4 ,the general consensus of opinion is that the remedy has a specific action upon tubercular tissues1 and is1 therefore1 applicable as a very delicate and sure reagent for discovering latent and diagnosing doubtful tuberculous processes4 ,regarding the curative effects of the remedy1 most reports agree that1 despite the comparatively short duration of its application1 many patients have shown more or less pronounced improvement4 ,it has been affirmed that in not a few cases even a cure has been established4 ,standing quite by itself is the assertion that the remedy may not only be dangerous in cases which have advanced too far--a fact which may forthwith be conceded--but also that it actually promotes the tuberculous process1 being therefore injurious4 ,during the past six weeks ,i myself have had opportunity to bring together further experiences touching the curative effects and diagnostic application of the remedy in the cases of about one hundred and fifty sufferers from tuberculosis of the most varied types in this city and in the ,moabit ,hospital4 ,i can only say that everything ,i have latterly seen accords with my previous observations4 ,there has been nothing to modify in what ,i before reported4 ,as long as it was only a question of proving the accuracy of my indications1 it was needless for any one to know what the remedy contained or whence it was derived4 ,on the contrary1 subsequent testing would necessarily be more unbiased1 the less people knew of the remedy itself4 ,now1 after sufficient confirmatory testing1 the importance of the remedy is proved1 my next task is to extend my study of the remedy beyond the field where it has hitherto been applied1 and if possible to apply the principle underlying the discovery to other diseases4 ,this task naturally demands a full knowledge of the remedy4 ,i therefore consider that the time has arrived when the requisite indications in this direction shall be made4 ,this is done in what follows4 ,before going into the remedy itself1 ,i deem it necessary for the better understanding of its mode of operation to state briefly the way by which ,i arrived at the discovery4 ,if a healthy guinea pig be inoculated with the pure cultivation of ,german ,kultur of tubercle bacilli1 the wound caused by the inoculation mostly closes over with a sticky matter1 and appears in its early days to heal4 ,only after ten to fourteen days a hard nodule presents itself1 which1 soon breaking1 forms an ulcerating sore1 which continues until the animal dies4 ,quite a different condition of things occurs when a guinea pig already suffering from tuberculosis is inoculated4 ,an animal successfully inoculated from four to six weeks before is best adapted for this purpose4 ,in such an animal the small indentation assumes the same sticky covering at the beginning1 but no nodules form4 ,on the contrary1 on the day following1 or the second day after the inoculation1 the place where the lymph is injected shows a strange change4 ,it becomes hard and assumes a darker coloring1 which is not confined to the inoculation spot1 but spreads to the neighboring parts until it attains a diameter of from #j4je to #a cm4 ,in a few days it becomes more and more manifest that the skin thus changed is necrotic1 finally falling off1 leaving a flat ulceration which usually heals rapidly and permanently without any involvement of the adjacent lymphatic glands4 ,thus the injected tubercular bacilli quite differently affect the skin of a healthy guinea pig from one affected with tuberculosis4 ,this effect is not exclusively produced with living tubercular bacilli1 but is also observed with the dead bacilli1 the result being the same whether1 as ,i discovered by experiments at the outset1 the bacilli are killed by a somewhat prolonged application of a low temperature or boiling heat or by means of certain chemicals4 ,this peculiar fact ,i followed up in all directions1 and this further result was obtained--that killed pure cultivations of tubercular bacilli1 after rinsing in water1 might be injected in great quantities under healthy guinea pig's skin without anything occurring beyond local suppuration4 ,such injections belong to the simplest and surest means of producing suppurations free from living bacteria4 ,tuberculous guinea pigs1 on the other hand1 are killed by the injection of very small quantities of such diluted cultivations4 ,in fact1 within six to forty-eight hours1 according to the strength of the dose1 an injection which is not sufficient to produce the death of the animal may cause extended necrosis to the skin in the vicinity of the place of injection4 ,if the dilution is still further diluted until it is scarcely visibly clouded1 the animals inoculated remain alive and a noticeable improvement in their condition soon supervenes4 ,if the injections are continued at intervals of from one to two days1 the ulcerating inoculation wound becomes smaller and finally scars over1 which otherwise it never does2 the size of the swollen lymphatic glands is reduced1 the body becomes better nourished1 and the morbid process ceases1 unless it has gone too far1 in which case the animal perishes from exhaustion4 ,by this means the basis of a curative process against tuberculosis was established4 ,against the practical application of such dilutions of dead tubercle bacilli there presented itself the fact that the tubercle bacilli are not absorbed at the inoculation points1 nor do they disappear in another way1 but for a long time remain unchanged1 and engender greater or smaller suppurative foci4 ,anything1 therefore1 intended to exercise a healing effect on the tuberculous process must be a soluble substance which would be liberated to a certain extent by the fluids of the body floating around the tubercle bacilli1 and be transferred in a fairly rapid manner to the juices of the body2 while the substance producing suppuration apparently remains behind in the tubercular bacilli1 or dissolves but very slowly4 ,the only important point was1 therefore1 to induce outside the body the process going on inside1 if possible1 and to extract from the tubercular bacilli alone the curative substance4 ,this demanded time and toil1 until ,i finally succeeded1 with the aid of a forty to fifty per cent4 solution of glycerine1 in obtaining an effective substance from the tubercular bacilli4 ,with the fluid so obtained ,i made further experiments on animals1 and finally on human beings4 ,these fluids were given to other physicians to enable them to repeat the experiments4 ,the remedy which is used in the new treatment consists of a glycerine extract1 derived from the pure cultivation of tubercle bacilli4 ,into the simple extract there naturally passes from the tubercular bacilli1 besides the effective substance1 all the other matter soluble in fifty per cent4 glycerine4 ,consequently1 it contains a certain quantity of mineral salts1 coloring substances1 and other unknown extractive matters4 ,some of these substances can be removed from it tolerably easily4 ,the effective substance is insoluble in absolute alcohol4 ,it can be precipitated by it1 though not1 indeed1 in a pure condition1 but still combined with the other extractive matter4 ,it is likewise insoluble in alcohol4 ,the coloring matter may also be removed1 rendering it possible to obtain from the extract a colorless1 dry substance containing the effective principle in a much more concentrated form than the original glycerine solution4 ,for application in practice this purification of the glycerine extract offers no advantage1 because the substances so eliminated are unessential for the human organism4 ,the process of purification would make the cost of the remedy unnecessarily high4 ,regarding the constitution of the more effective substances1 only surmises may for the present be expressed4 ,it appears to me to be derivative from albuminous bodies1 having a close affinity to them4 ,it does not belong to the group of so-called toxalbumins1 because it bears high temperatures1 and in the dialyzer goes easily and quickly through the membrane4 ,the proportion of the substance in the extract to all appearance is very small4 ,it is estimated at fractions of one per cent41 which1 if correct1 we should have to do with a matter whose effects upon organisms attacked with tuberculosis go far beyond what is known to us of the strongest drugs4 ,regarding the manner in which the specific action of the remedy on tuberculous tissue is to be represented1 various hypotheses may naturally be put forward4 ,without wishing to affirm that my view affords the best explanation1 ,i represent the process myself in the following manner3 ,the tubercle bacilli produced when growing in living tissues1 the same as in artificial cultivations1 contain substances which variously and notably unfavorably influence living elements in their vicinity4 ,among these is a substance which in a certain degree of concentration kills or so alters living protoplasm that it passes into a condition that ,weigert describes as coagulation necrosis4 ,in tissue thus become necrotic the bacillus finds such unfavorable conditions of nourishment that it can grow no more and sometimes dies4 ,this explains the remarkable phenomenon that in organs newly attacked with tuberculosis1 for instance in guinea pigs' spleen and liver1 which then are covered with gray nodules1 numbers of bacilli are found1 whereas they are rare or wholly absent when the enormously enlarged spleen consists almost entirely of whitish substance in a condition of coagulation necrosis1 such as is often found in cases of natural death in tuberculous guinea pigs4 ,the single bacillus cannot1 therefore1 induce necrosis at a great distance1 for as soon as necrosis attains a certain extension the growth of the bacillus subsides1 and therewith the production of the necrotizing substance4 ,a kind of reciprocal compensation thus occurs1 causing the vegetation of isolated bacilli to remain so extraordinarily restricted1 as1 for instance1 in lupus and scrofulous glands4 ,in such cases the necrosis generally extends only to a part of the cells1 which then1 with further growth1 assume the peculiar form of riesen zelle1 or giant cells4 ,thus1 in this interpretation1 follow first the explanation ,weigert gives of the production of giant cells4 ,if now one increased artificially in the vicinity of the bacillus the amount of necrotizing substance in the tissue1 the necrosis would spread a greater distance4 ,the conditions of nourishment for the bacillus would thereby become more unfavorable than usual4 ,in the first place the tissue which had become necrotic over a large extent would decay and detach itself1 and where such were possible would carry off the inclosed bacilli and eject them outwardly1 so far disturbing their vegetation that they would much more speedily be killed than under ordinary circumstances4 ,it is just in looking at such changes that the effect of the remedy appears to consist4 ,it contains a certain quantity of necrotizing substance1 a correspondingly large dose of which injures certain tissue elements even in a healthy person1 and perhaps the white blood corpuscles or adjacent cells1 thereby producing fever and a complication of symptoms1 whereas with tuberculous patients a much smaller quantity suffices to induce at certain places1 namely1 where tubercle bacilli are vegetating and have already impregnated the adjacent region with the same necrotizing matter1 more or less extensive necrosis of the cells1 with the phenomena in the whole organism which result from and are connected with it4 ,for the present1 at least1 it is impossible to explain the specific influence which the remedy1 in accurately defined doses1 exercises upon tuberculous tissue1 and the possibility of increasing the doses with such remarkable rapidity1 and the remedial effects which have unquestionably been produced under not too favorable circumstances4 ,of the consumptive patients whom he described as temporarily cured1 two have been returned to the ,moabit ,hospital for further observation4 ,no bacilli have appeared in their sputum for the past three months1 and their phthisical symptoms have gradually and completely disappeared4 99 99 99 99 99 ,,can ,,we ,,separate ,,animals ,,from ,,plants8 ,by ,,andrew ,,wilson4 ,one of the plainest points connected with the study of living things is the power we apparently possess of separating animals from plants4 ,so self-evident appears this power that the popular notion scoffs at the idea of science modestly disclaiming its ability to separate the one group of living beings from the other4 ,is there any danger of confusing a bird with the tree amid the foliage of which it builds its nest1 or of mistaking a cow for the grass it eats8 ,these queries are1 of course1 answerable in one way only4 ,unfortunately 7for the querists71 however1 they do not include or comprehend the whole difficulty4 ,they merely assert1 what is perfectly true1 that we are able1 without trouble1 to mark off the higher animals from the higher plants4 ,what science inquires is1 whether we are able to separate all animals from all plants1 and to fix a definite boundary line1 so as to say that all the organisms on the one side of the line are assuredly animals1 while all the others on the opposite side of the line may be declared to be truly plants4 ,it is exactly this task which science declares to be among the impossibilities of knowledge4 ,away down in the depths of existence and among the groundlings of life the identity of living things becomes of a nature which is worse than confusing1 and which renders it a futile task to attempt to separate the two worlds of life4 ,the hopelessness of the task1 indeed1 has struck some observers so forcibly that they have proposed to constitute a third kingdom--the ,regnum ,protisticum--between the animal and the plant worlds1 for the reception of the host of doubtful organisms4 ,this third kingdom would resemble the casual ward of a workhouse1 in that it would receive the waifs and strays of life which could not find a refuge anywhere else4 ,a very slight incursion into biological fields may serve to show forth the difficulties of naturalists when the task of separating animals from plants is mooted for discussion4 ,to begin with1 if we suppose our popular disbeliever to assert that animals and plants are always to be distinguished by shape and form1 it is easy enough to show him that here1 as elsewhere1 appearances are deceptive4 ,what are we to say of a sponge1 or a sea anemone1 of corals1 of zoophytes growing rooted from oyster shells1 of sea squirts1 and of sea mats8 ,these1 each and all of them1 are true animals1 but they are so plant-like that1 as a matter of fact1 they are often mistaken by seaside visitors for plants4 ,this last remark holds especially true of the zoophytes and the sea mats4 ,then1 on the other hand1 we can point to hundreds of lower plants1 from the yeast plant onward1 which show none of the ordinary features of plant life at all4 ,they possess neither roots1 stems1 branches1 leaves1 nor flowers1 so that on this first count of the indictment the naturalist gains the day4 ,power of movement1 to which the popular doubter is certain to appeal1 is an equally baseless ground of separation4 ,for all the animals ,i have above named are rooted and fixed1 while many true plants of lower grade are never rooted at all4 ,the yeast plant1 the ,alg that swarm in our ponds1 and the diatoms that crowd the waters1 exemplify plants that are as free as animals2 and many of them1 besides1 in their young state especially 7e4g41 the seaweeds71 swim about freely in the water as if they were roving animalcules4 ,on the second count1 also1 science gains the day2 power of motion is no legitimate ground at all for distinguishing one living being as an animal1 while absence of movement is similarly no reason for assuming that the fixed organism must of necessity be a plant4 ,then comes the microscopic evidence4 ,what can this wonder glass do in the way of drawing boundary lines betwixt the living worlds8 ,the reply again is disappointing to the doubter2 for the microscope teaches us that the tissues of animals and plants are built upon kindred lines4 ,we meet with cells and fibers in both4 ,the cell is in each case the primitive expression of the whole organism4 ,beyond cells and fibers we see the wonderful living substance1 protoplasm1 which is alike to our senses in the two kingdoms1 although1 indeed1 differing much here and there in the results of its work4 ,on purely microscopic grounds1 we cannot separate animals from plants4 ,there is no justification for rigidly assuming that this is a plant or that an animal on account of anything the microscope can disclose4 ,a still more important point in connection with this protoplasm question consists in the fact that as we go backward to the beginnings of life1 both in animals and plants1 we seem to approach nearer and nearer to an identity of substance which baffles the microscope with all its powers of discernment4 ,every animal and every plant begins existence as a mere speck of this living jelly4 ,the germ of each is a protoplasm particle1 which1 whatever traces of structure it may exhibit1 is practically unrecognizable as being definitely animal or plant in respect of its nature4 ,later on1 as we know1 the egg or germ shows traces of structure in the case of the higher animals and plants2 while even lowly forms of life exhibit more or less characteristic phases when they reach their adult stage4 ,but1 of life's beginnings1 the microscope is as futile as a kind scientific touchstone for distinguishing animals from plants as is power of movement1 or shape1 or form4 ,a fourth point of appeal in the matter is found within the domain of the chemist4 ,chemistry1 with its subtile powers of analysis1 with its many-sided possibilities of discovering the composition of things1 and with its ability to analyze for us even the light of the far distant stars1 only complicates the difficulties of the biologist4 ,for1 while of old it was assumed that a particular element1 nitrogen1 was peculiar to animals1 and that carbon was an element peculiar to plants1 we now know that both elements are found in animals1 just as both occur in plants4 ,the chemistry of living things1 moreover1 when it did grow to become a staple part of science1 revealed other and greater anomalies than these4 ,it showed that certain substances which were supposed to be peculiar to plants1 and to be made and manufactured by them alone1 were also found in animals4 ,chlorophyl is the green coloring matter of plants1 and is1 of course1 a typical product of the vegetable world2 yet it is made by such animals as the hydra of the brooks and ponds1 and by many animalcules and some worms4 ,starch is surely a typical plant product1 yet it is undoubtedly manufactured1 or at least stored up1 by animals--a work illustrated by the liver of man himself1 which occasionally produces sugar out of its starch4 ,again1 there is a substance called cellulose1 found well nigh universally in plants4 ,of this substance1 which is akin to starch1 the walls or envelopes of the cells of plant tissues are composed4 ,yet we find those curious animals1 the sea squirts1 found on rocks and stones at low-water mark1 manufacturing cellulose to form part and parcel of the outer covering of their sac-like bodies4 ,here it is as if the animal1 like a dishonest manufacturer1 had infringed the patent rights of the plant4 ,on the fourth count1 then--that of chemical composition--the verdict is that nothing that chemistry can teach us may serve definitely1 clearly1 and exactly to set a boundary line or to erect a partition wall between the two worlds of life4 ,there yet remains for us to consider a fifth head--that of the food4 ,in the matter of the feeding of the two great living worlds we might perchance light upon some adequate grounds for making up the one kingdom from the other4 ,what the consideration of form1 movement1 chemical composition1 and microscopic structure could not effect for us in this way1 it might be supposed the investigation of the diet of animals and plants would render clear4 ,our hopes of distinguishing the one group from the other by reference to the food on which animals and plants subsist are1 however1 dashed to the ground2 and the diet question leaves us1 therefore1 when it has been discussed1 in the same quandary as before4 ,nevertheless1 it is an interesting story1 this of the nutrition of animals and plants4 ,a large amount of scientific information is to be gleaned from such a study1 which may very well be commenced by our having regard to the matters on which a green plant feeds4 ,i emphasize the word green1 because it so happens that when a plant has no chlorophyl 7as green color is named in the plant world7 its feeding is of diverse kind to that which a green plant exhibits4 ,the mushroom or other fungus may be taken as an illustration of a plant which represents the non-green race1 while every common plant1 from a bit of grass to an oak tree1 exemplifies the green-bearing order of the vegetable tribes4 ,suppose we were to invite a green plant to dinner1 the menu would have to be very differently arranged from that which would satisfy a human or other animal guest4 ,the soup would be represented for the plant's delectation by water1 the fish by minerals1 the joint by carbonic acid gas1 and the dessert by ammonia4 ,on these four items a green plant feeds1 out of them it builds up its living frame4 ,note that its diet is of inorganic or non-living matter4 ,it derives its sustenance from soil and air1 yet out of these lifeless matters the green plant elaborates and manufactures its living matter1 or protoplasm4 ,it is a more wonderful organism than the animal1 for while the latter can only make new protoplasm when living matter is included in its food supply1 the green plant1 by the exercise of its vital chemistry1 can transform that which is not living into that which is life-possessing4 ,the green plant in other words1 raises non-living into living matter1 while the animal can only transform living matters into its like4 ,this is why the plant is called a constructive organism1 while the animal is1 contrariwise1 named a destructive one4 ,the result of the plant's existence is to build up1 that of the animal's life is to break down its substance1 as the result of its work1 into non-living matter4 ,the animal's body is1 in fact1 breaking down into the very things on which the green plant feeds4 ,we ourselves are perpetually dissipating our substance in our acts of life and work into the carbonic acid1 water1 ammonia1 and minerals on which plants feed4 ,we die daily in as true a sense as that in which the apostle used the term4 ,and out of the debris of the animal frame the green plant builds up leaf and flower1 stein and branch1 and all the other tokens of its beauty and its life4 ,if1 then1 an animal can only live upon living matter--that is to say on the bodies of other animals or of plants--with water1 minerals and oxygen gas from the air thrown in to boot1 we might be tempted to hold that in such distinctive ways and works we had at last found a means of separating animals from plants4 ,unfortunately1 this view may be legitimately disputed and rendered null and void1 on two grounds4 ,first of all1 the mushrooms and their friends and neighbors1 all true plants1 do not feed as do the green tribes4 ,and secondly1 many of the green plants themselves can be shown to have taken very kindly to an animal mode of diet4 ,a mushroom1 thus1 because it has no green color1 lives upon water1 oxygen1 minerals1 and organic matter4 ,you can only grow mushrooms where there is plenty of animal matter in a state of decay1 and as for the oxygen1 they habitually inhale that gas as if they were animals4 ,non-green plants thus want a most characteristic action of their green neighbors4 ,for the latter in daylight take in the carbonic acid gas1 which is composed of carbon and oxygen4 ,under the combined influence of the green color and the light1 they split up the gas into its two elements1 retaining the carbon for food and allowing the oxygen to escape to the atmosphere4 ,alas6 however1 in the dark our green plant becomes essentially like an animal as regards its gas food1 for then it is an absorber of oxygen1 while it gives off carbonic acid4 ,if to take in carbonic acid and to give out oxygen be held to be a feature characteristic of a plant1 it is one1 as has been well said1 which disappears with the daylight in green plants1 and which is not witnessed at all in plants that have no green color4 ,so far1 we have seen that not even the food of plants and animals can separate the one kingdom of life from the other4 ,the mushroom bars the way and the green plant's curious behavior by night and by day respectively1 in the matter of its gas food1 once more assimilates animal life and plant life in a remarkable manner4 ,still more interesting is the fact1 already noticed1 that even among the green tribes there are to be found many and various lapses from the stated rules of their feeding4 ,thus what are we to say of the parasitic mistletoe1 which1 while it has grown leaves of its own1 and can1 therefore1 obtain so much carbon food from the air on its own account1 nevertheless drinks up the sap of the oak or apple which forms its host1 and thus illustrates the spectacle of a green plant feeding like an animal1 on living matter8 ,or1 what may we think of such plants as the sundew1 the ,venus' fly trap1 the pitcher plants1 the side saddle plants1 the butterworts and bladderworts1 and others of their kind1 which not only capture insects1 often by ingenious and complex lures1 but also digest the animal food thus captured8 ,a sundew thus spreads out its lure in the shape of its leaf studded with sensitive tentacles1 each capped by a glistening drop of gummy secretion4 ,entangled in this secretion1 the fly is further fixed to the leaf by the tentacles which bend over it and inclose it in their fold4 ,then is poured out upon the insect's body a digestive acid fluid1 and the substance of the dissolved and digested animal is duly absorbed by the plant4 ,so also the ,venus' fly trap captures insects by means of its leaf1 which closes upon the prey when certain sensitive hairs have given the signal that the animal has been trapped4 ,within the leaf the insect is duly digested as before1 and its substance applied to the nutrition of the plant4 ,such plants1 moreover1 cannot flourish perfectly unless duly supplied with their animal food4 ,such illustrations of exceptions to the rule of green plant feeding simply have the effect of abolishing the distinctions which the diet question might be supposed to raise between animals and plants4 ,we may return to the sundews and other insect catchers2 meanwhile1 ,i have said enough to show that to the question1 ,can we separate animals from plants8 a very decided negative reply must be given4 ,life everywhere exhibits too many points of contact to admit of any boundary line being drawn between the two great groups which make up the sum total of organic existence4--,illustrated ,london ,news4 99 99 99 99 99 ,,the ,,recovery ,,of ,,silver ,,and ,,gold ,,from ,,plating ,,and ,,gilding ,,solutions4 ,in view of the rapid development and extension of the methods of electro-plating with silver and gold1 and of the large amount of spent liquors containing silver or gold thus produced1 it has long been desirable to find methods by which these metals can be recovered from the spent liquors4 ,the processes hitherto adopted generally necessitate the tedious and unpleasant evaporation of the cyanide liquors1 or else involve a series of chemical operations which are somewhat difficult to carry out1 so that actually the used-up baths are sold to some firm which undertakes this recovery as a particular branch of its business4 ,a process invented by ,stockmuir and ,fleischmann1 and worked out by them in the chemical laboratory of the ,bavarian ,industrial ,museum1 is1 however1 exceedingly simple1 and is employed in many establishments4 ,in order to remove silver from a potassium cyanide silver solution1 it is only necessary to allow a clean piece of plate zinc to remain in the liquid for two days2 even better results are obtained by the use of iron conjointly with the zinc4 ,in the first case1 the silver often adheres firmly to the zinc1 while in the second it always separates out as a powder4 ,it is then only necessary to wash the precipitated powder1 which usually contains copper 7since spent silver solutions always contain copper71 dry it1 and then dissolve it in hot concentrated sulphuric acid1 water being added1 and the dissolved silver precipitated by strips of copper4 ,the silver thus obtained is perfectly pure4 ,if the amount of copper present is only small1 it can usually be removed by fusing the precipitated powder with a little niter and borax4 ,in this way a spent silver bath was found to contain per liter #ast experiment #a4egjf grms4 #b;d #a4efid ------ ,mean #a4egjj ,the presence of silver could not be qualitatively ascertained in the residual liquor4 ,although sheet zinc1 or zinc and iron sheets1 serve so well for the precipitation of silver1 they cannot be employed for the recovery of gold4 ,the latter separates out in such a case very incompletely and as a firmly adhering lustrous film in the zinc4 ,on the other hand1 finely divided zinc1 the so-called zinc dust1 is an excellent substance to employ for precipitating gold quantitatively and in the form of powder from spent cyanide liquors4 ,when zinc dust is added to a spent gold bath and the liquid periodically stirred or shaken1 all the gold is precipitated in two or three days4 ,the amount of zinc to be added naturally depends on the quantity of gold present4 ,freshly prepared gold baths for gilding in the cold contain on the average #c4e grms4 gold per liter1 while those used for the hot process contain #aj4ge grms4 ,to precipitate all the gold in the original bath1 #a4gd grms4 or #j4cg-j4e grms4 zinc dust would be necessary1 and1 of course1 a much smaller quantity would be sufficient for the spent liquors4 ,since the precipitation takes place more rapidly when an excess of zinc dust is present1 it is generally advisable to add or at the most kilo1 of zinc dust to every #ajj liters of solution4 ,the precipitated gold1 which contains zinc dust and usually silver and copper1 is washed1 freed from zinc by hydrochloric acid1 and then from silver and copper by nitric acid and thus obtained pure4 ,a spent bath treated in this way gave the following amounts of gold per liter3 #ast experiment #j4bfbf #b;d #j4bfcd ,mean #j4bfcj grms4 ,the presence of gold in the residual cyanide solution could not be qualitatively detected4 ,the potassium cyanide of the solutions obtained by this process should be converted into ferrocyanide by heating with ferrous sulphate and milk of lime1 since this substance is not poisonous and can therefore be got rid of without danger4 ,it would1 however1 be more economical and1 considering the large amount of cyanide present1 more profitable to work it up into ,prussian blue4 99 99 99 99 99 ,a ,,new ,,catalogue ,,of ,,valuable ,,papers ,contained in ,,scientific ,,american ,,supplement during the past ten years1 sent free of charge to any address4 ,,munn ,,co41 #cfa ,broadway1 ,new ,york4 99 99 99 99 99 ,,the ,,scientific ,,american ,,architects ,,and ,,builders ,,edition #b4ej ,a ,,year4 ,,single ,,copies1 #be ,,cts4 ,this is a ,special ,edition of the ,,scientific ,,american1 issued monthly--on the first day of the month4 ,each number contains about forty large quarto pages1 equal to about two hundred ordinary book pages1 forming1 practically1 a large and splendid ,magazine of ,architecture1 richly adorned with elegant platen in colors and with fine engravings1 illustrating the most interesting examples of modern ,architectural ,construction and allied subjects4 ,a special feature is the presentation in each number of a variety of the latest and best plans for private residences1 city and country1 including those of very moderate cost 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