518 FOODS AND FOOD ADULTERANTS. 



Tenth. After filtering or decanting as above, lio\v did yon treat it, or where did yon. 

 keep it before weighing ? 



Answer. Dried it in an air-bath. 



Eleventh. Did you weigh the residue while ou a filter or in a beaker, or evaporat- 

 ing dish, or how ? 



Answer. On the filter. 



Twelfth. What was the exact weight of the residue found ? 



Answer. I have kept a record only of the results; the only figures that I can find 

 just now of the actual weight of the residue are the following : 

 4.25 grams of lard, No. 3, gave 275 milligrams. 

 4.7 grams of pure lard gave 350 milligrams. 

 19.74 grams of pure lard gave 200 milligrams. 

 9.4 grams of lard, No. 3, gave 600 milligrams. 



In making his sample test of pure lard he took his material chiefly from the loaf 

 lard and from the sides of the liog; some of it was salted and some was fresh ; before 

 rendering it lie cut the material into very small pieces, and allowed it to stand in a 

 large volume of cold water for some time to take the salt out; it was* then filtered 

 out in pans and rendered on a sand-bath, that is, pans full of sand and heated from 

 below, so as to get an even temperature and not burn the lard ; after rendering, the 

 lard was filtered, in order to remove any tissue or foreign matter from it ; he is quite 

 sure he got, into 1 per cent., all the lard there was in the material ; the temperature 

 at which the lard was rendered was 175 to 200 degrees centigrade,* which is much 

 higher than is necessary to break up the cells and melt all the steariue there may bo 

 in the lard. In getting the samples of lard from a packing-house he asked for pure 

 prime steam lard ; in testing that sample he found it to run a little higher in steariue 

 than the lard he rendered himself; he can not, of course, say that the sample procured 

 from the packing-house was perfectly pure, because he did not himself see it ren- 

 dered. The solvent he used was absolute alcohol and the strongest of Squibb's ether ; 

 he always measured the solvent; the melted lard was at about 70 or 75 degrees cen- 

 tigrade, when the solvent was applied, so as to be sure the palmitine would remain 

 in solution. After the solvent was mixed with the lard he did not ascertain its tem- 

 perature ; he had no use for that ; the lard was allowed to stand in the solution be- 

 fore decanting about fifteen to eighteen and sometimes twenty-four hours, during 

 which time it was kept in cold water, at a temperature 12 to 15 degrees centigrade, 

 always below 15 and sometimes a little lower than 12; he does not know what the 

 temperature of the room was in which the mixture was allowed to remain. The mixt- 

 ure of alcohol and ether, after being added to the lard, was well shaken ; after the 

 first solvent had been decanted, he replaced it with about half as much of fresh solv- 

 ent as had been first used, shook it well and often for two or three hours, and then 

 allowed it to stand ten or twelve hours or so, sometimes over night, again shook it 

 several times, then filtered, and in order to avoid an error that might arise from the 

 liquid evaporating and leaving a part of the residue too hard, ho pressed it between 

 blotting papers so as to absorb all that was not properly residue, then dried in an 

 oven and weighed it; sometimes, while it was on the filter, he poured more of the 

 solvent on it and again filtered so as to dispose of all that was soluble. He can not 

 see what the residue could contain except stearine, unless it might be a small quan- 

 tity of palmitine; he tested the residue by determining its melting point and its 

 solubility, and that showed it to be stearino ; there is no difference in the chemieal 

 characteristics of the pure stearine procured from the fat of beef, mutton, or pork ; 

 they are the same thing as far as he knows, and ho does not know of any difference 

 in the chemical reaction of these ditfereut kinds of stearine ; he does not attempt to 

 distinguish between them ; ho docs not know certainly how much pure stearine lard 

 actually contains ; it varies ; he has never found it to exceed 2 per cent, in pure lard, 

 and sometimes it runs a* low us three-quartan of 1 per cent, wlien subjects! In the 



* Prnliiililv Fiilirenlii-il is meant. 



