LARD AND LARD ADULTERATIONS. 535 



oil, liad cottonseed oil in it. The samples of Fowler lard did not give the cottonseed 

 oil appearance when tested by the spectroscope, but acted in all respects the same as 

 the pure prime steam lard did. He does not attach much importance to this test, and 

 can only say that so far as the examination of the Fowler lard by this test is con- 

 cerned, the results were negative. 



When examined by transmitted light cottonseed oil has a yellowish color, which 

 neither pure lard nor tallow has, but all mixtures of lard and cottonseed oil have this 

 color. The Fowler lards failed to show any appearance of this color when examined 

 by transmitted light. 



The cottonseed oil he used in all these experiments was refined oil. He has never 

 used the bleached or colorless oil for such experiments. The test by transmitted 

 light would be of no value whatever in detecting the colorless oil. 



Finally, in respect to the color test for the detection of cottonseed oil: When he 

 testified two days since, he had spoken cautiously and not very confidently of the 

 value of this process. At that time he had just come from the laboratory where they 

 (himself and others) had met with a difficulty which at that time none of them could 

 solve. This arose from their having used something they did not know anything 

 about. This difficulty has, however, been since explained, and ho is now fully pre- 

 pared to make a positive statement in regard to the value of the sulphuric-acid test 

 as a means of detecting an admixture of cottonseed oil in lard, and has joined with 

 Professor Sharpless and others in the statement read by Professor Sharpless in that 

 gentleman's final testimony in regard to the value of that test. The expression of this 

 paper (see pp. 233,234, which the witness read) is his deliberate judgment upon tho 

 question of the reliability of the color test for cottonseed oil ; and in view of all his ex- 

 aminations of the samples 1, 2, and 3 of Fowler lard, he is now prepared to express a 

 positive opinion that these samples do not contain any cottonseed oil. He did not, as 

 he has said, use any bleached oil in this process, but other gentlemen did, who have 

 given, or will give, evidence on that point. In all the oil ho has used he always gets 

 the color reaction peculiar to cottonseed eil, not always to exactly the same extent, 

 but so sufficiently and clearly marked as to be unmistakable, and the absence of it is 

 proof positive, to his mind, that there ia no cottonseed oil in the samples of Fowler 

 lard he has examined. 



CERTIFICATE OF PROF. R. A. WITTHAUS.* 



CHICAGO, July 5, 1883. 



This is to certify that I have made chemical examinations of three samples of lard 

 marked, respectively, Nos. 1, 2, and 3, Fowler, without obtaining the slightest evi- 

 dence of the presence of any impurity. I therefore consider them as being samples 

 of pure prime steam lard. 



R. A. WITTHAUS. 



Professor Witthaus also exhibited a table showing the results of. five experiments 

 with modifications of Husson, showing the varying proportions of insoluble residue left 

 by ether and alcohol. In the first four experiments the residue was washed with lOce 

 of absolute alcohol, in the fifth with 30cc.t 



* Op. cit., p. 254. t Op. cit.. table, p. 249. 



