764 EXPEEIMENT STATION" EECOED. 



tain an added poisonous or deleterious ingredient which may render such 

 articles of food injurious to health, whether taken in large quantities or in 

 small quantities. In any event, there is an element of danger in coppered foods 

 which, from a physiological standpoint, should not be ignored." 



Histological examination of the tissues of dogs and monkeys, T. Smith (pp. 

 449-461).- — This report gives the results of autopsies made on animals used in 

 the feeding experiments conducted by Chittenden. 



"A comparison of the gross and minute pathological conditions found in the 

 8 dogs shows a relatively slight yield from these methods of inquiry. A few 

 facts, however, seem worthy of note. 



" There has been no noticeable influence of the copper salts on the parasites 

 in the digestive tract. Thus, dogs Nos. 1 and 3 were from the same litter and 

 probably infested alike with worms at the start. But the autopsy showed no 

 difference, although No. 3 had been fed with coppered peas and No. 1 with 

 uncoppered peas. Parasites were also present in the other dogs fed with cop- 

 pered peas. ... In general it can be stated that the feeding with coppered 

 peas did not have any decided vermifuge action. . . . Even the copper sulphate 

 did not completely remove intestinal parasites. 



" Very little, if any, appreciable differences were found between the con- 

 trols on the one hand (Nos. 1 and 2) and the dogs fed with coppered peas on 

 the other (Nos. 3 to 6). There was some fat in the liver of No. 3 as compared 

 with his (control) brother No. 1. More than this can not be stated. There is, 

 however, a distinction to be drawn between the dogs fed with coppered peas 

 and those fed with copper sulphate. No. 8 was chloroformed before the close 

 of the experiment because ill. In both No. 7 and No. 8 there was present an 

 interstitial inflammation of the kidneys localized in the cortex, which was 

 absent in all the others. The kidney lesions in Nos. 1 and 3 were, as already 

 stated, due to parasites. In No. 8 there was also other lesions (extensive, 

 fresh pigment in the spleen, leucocytosis)." 



In the case of monkeys " the microscopic examination, as far as it went, did 

 not reveal any differences between control and treated monkeys. It would 

 seem as if this species of animal was better able to neutralize the poisonous 

 action of copper sulphate than the dog." 



From a study of these 4 reports, the Referee Board reached the following 

 conclusion : 



" Copper salts used in the coloring of vegetables as in commercial practice 

 can not be said to reduce, or lower, or injuriously affect the quality or strength 

 of such vegetables, as far as the food value is concerned. 



" Copper salts used in the greening of vegetables may have the effect of con- 

 cealing inferiority, inasmuch as the bright green color imparted to the vege- 

 tables simulates a state of freshness they may not have possessed before 

 treatment. 



" In attempting to define a large quantity of copper, regard must be had to 

 the maximum amount of greened vegetables which might be consumed daily. 

 A daily dose of 100 gm. of coppered peas or beans, which are the most highly 

 colored vegetables in the market, would not ordinarily contain more than 100 

 to 150 mg. of copper. Such a bulk of greened vegetables is so large, however, 

 that it would hardly be chosen as a part of a diet for many days in succession. 

 Any amount of copper above 150 mg. daily may therefore be considered ex- 

 cessive in practice. A small quantity is that amount which, in the ordinary 

 use of vegetables, may be consumed over longer periods. From this point of 

 view, 10 to 12 mg. of copper may be regarded as the upper limit of a small 

 quantity. 



