LARD AND LAED ADULTERATIONS. 529 



CERTIFICATE OF WALTER S. IIAIXES.* 



CHICAGO, 7fy2, 1883. 



This is to certify that I have examined the specimens of lard delivered to me by 

 Col. Ezra Taylor and numbered 1, 2, and 3, and also the specimens placed in my hands 

 by Dr. Robert Tilley, numbered 1, 2, and 3, and that I find them pure lard and unadult- 

 erated with tallow or cottonseed oil. 



WALTER S. HAIXES. 



METHOD EMPLOYED BY PROFESSOR HAIXES.t 



To test for the presence of cottonseed oil I used the color test with strong sulphuric 

 acid : from 5 to 10 grains of the lard are stirred up with one or two drops of the acid 

 and the color produced is noted. Pure lard thus treated gives a color ranging from 

 salmon to slate, cottonseed oil a dark olive brown, while lard mixed with cotton- 

 seed oil produces a well-marked mixture of the two colors. 



To test for the presence of tallow I make a solution of lard in some slightly warmed 

 solvent, such as turpentine, ether, or ether and alcohol ; after a number of hours the 

 crystals thrown down are examined (preferably after washing with a little absolute 

 alcohol, or ether and alcohol) by the aid of a microscope ; the form of crystals indicates 

 whether the lard has been adulterated or not. 



WALTER S. HAIXES. 



In explanation of his results, Professor Haines said:! 



In saying that he used essentially Professor Delafontaine's process, he meant that 

 ho had endeavored to follow the spirit of that process as he understood it. Pro- 

 fessor Delafontaine insists that his examinations of the lard were all conducted com- 

 paratively with samples of known purity; and as his own were conducted in that 

 way, it makes but little difference what temperature is employed ; he always used 

 the same temperature for the examination of the samples in question. He thinks 

 Professor Delafontaine's process is not sufficiently accurately given to admit of be- 

 ing followed with entire precision ; he does not now remember the temperature 

 Professor Delafontaiue used ; he read that gentleman's certificate and evidence in 

 this case in respect to his process. He (Prof. D.) states that any chemist, on read- 

 ing his certilicate, will be able to tell his process. The certificate does not allude to 

 temperature, and he concludes that, as nothing was said in it about the temperature 

 employed, it was considered by Professor Delafontaine as of minor importance, or no 

 importance; it is true, on cross-examination, Professor Delafontaine did mention the 

 temperature, but ho concludes that when a chemist presents with deliberation, in 

 writing, an account of his process, and states, in connection with the certificate, that 

 it is amply sufficient fpr any chemist to follow, and has excluded any mention of tem- 

 perature in the certificate, the party attaches to temperature a very trivial impor- 

 tance, or no importance at all; it might have been considered an accidental omis- 

 sion, but for the fact that it was insisted that he should give all essential particulars 

 of his process, and after the certificate was submitted, ho, again and again, insisted 

 that everything essential was stated in the certificate ; and in view of these facts he 

 (the witness) can not consider that the omission was by an oversight, especially as 

 when , on the cross-examination, the temperature was developed it was not then spoken 

 of as being essential. In all his experiments of treating the lard under consideration, 

 concerning which he has testified, he either did tlie work himself, or saw it done from 

 beginning to end; those performed in his own laboratory were conducted entirely by 

 himself, in person, and whenever he left the laboratory, while the process was going 

 on, the room was securely locked. 



* P. 219. t Op. cit., pp. 219, 220. t Op. cit., pp. 220, 223. 



17319 pt, 4 9 



