LARD AND LARD ADULTERATIONS. 533 



which is naturally rich in steariue should be adulterated with one which is rich in 

 oleiue, he thinks chemistry could very easily detect that adulteration ; there are, 

 however, several fats which are so similar to each other, in respect to the proportions 

 of the constituents they contain, that when they are mixed it is a very difficult mat- 

 ter for chemistry to detect the mixture. The best method ho could think of wa 

 the separation of the stearine from the oleine, if that could be effected ; but there is 

 no method by which this can be entirely or anything like entirely done. If fats are 

 treated, in comparison, with some substance which will partly separate the stearine, 

 but leave some behind, and then that which is left behind in the one is compared 

 with that left behind in the other, both being accurately ascertained, and one is 

 found to be much larger than it should be, it is strong ground for suspicion in one's 

 mind that there is something the matter with it, without, perhaps, being able to say 

 exactly what has been put into it. In order to test a sample of lard by this process 

 it must first be known what standard lard really contains, or, if tallow or any other 

 fat, what that fat contains ; this, however, can not be ascertained from the books, 

 because, iu respect to reliable data on the subject, they are singularly silent. It is 

 stated repeatedly, in the books, that lard varies in its composition, depending on a 

 variety of causes, such as the dryness and other conditions of the food on which 

 the animal from which it was produced was fed, the season of the year when fed or 

 when killed, etc. No one seems to have made so complete an investigation of the 

 subject as to state to what extent these variations may go, hence it is absolutely nec- 

 essary, in an examination of lard, to first get something that may be considered a 

 standard of pure lard, to know what is pure lard, and to make an exhaustive inves- 

 tigation of the subject. There ought to be a very extensive investigation of different 

 specimens of lard, so as to find out what variations in the constituents are possible. 



For the purposes of this investigation, he procured at the outset a sample of lard 

 known to be pure, with which comparisons could be made as the investigations pro- 

 gressed ; and then if, on a comparative examination, the lards submitted for examina- 

 tion were found to conduct themselves in all respects in the same manner, and no 

 differences were found in them, the conclusion would be justified that tbe lards to be 

 tested were pure. In the process of examination, he in the first place applied Husson's 

 method, and also a modification of that method, suggested from reading the testimony 

 of Professor Delafontaine. Ho also applied the elaidine test and the pattern test, and 

 he treated them with sulphuric acid. lie also examined these samples by means of 

 the spectroscope and by transmitted light, and he has to some extent examined them 

 microscopically; and ho can say that, after all the examinations which he has been 

 able to give to the samples of lard submitted to him by Professor Haiues, his only 

 conclusion is that he can find no impurities whatever in them. 



In his examinations he has paid particular attention to the method described by 

 Professor Delafontaine, in that gentleman's testimony in this case. That is not the 

 method described in the books, and known as Husson's method, but is a modification 

 of that method to suit the case of lard. It depends upon the relative amount of residue 

 remaining after treatment with alcohol and ether, and he has to eay that if that 

 method is a good and reliable method, then, beyond any possible question in his mind, 

 the samples 1, 2, and 3 submitted to him are pure lard. If it is not a reliable method 

 it proves nothing. He is not prepared to absolutely condemn the method, for the 

 subject has never been studied, so far as he knows, with that care that would warrant 

 the basing of positive conclusions upon that process of determining it. It is possible 

 '.bat there is the germ of a good method in it ; but, as described by Professor Delafon- 

 taine, he is quire confident it could never be used to prove positively whether lard is 

 pure or impure. In respect to Husson's method, without any modification, he should 

 suy most emphatically that it is not a reliable process for determining the adultera- 

 tion of lard. The Blythe pattern process is, as ho understands it, the same as \vhat 

 is known as "cohesion figures." There is some confusion in the use of terms in de- 

 scribing matters of this sort. He is, however, quite sure that the process called the 



