FOODS HUMAN NUTRITION. 763 



I do not believe such a reteiitiuu uL u iieavy metal can be a negligible matter 

 even in tbe complete absence of present symptoms referable thereto ; the whole 

 tenor of the pharmacology of the heavy metals is contrary to such an interpre- 

 tation. It will be only safe to exclude the retention of a metal like copper from 

 tht' body. The retention in the case of the subjects of this experiment followed 

 ingestions of copper that could not be called large. And apparently such re- 

 tention might be expected to follow any ingestion of coppered vegetables. Under 

 these circumstances the ingestion of vegetables colored with copper constitutes 

 a menace to health." 



Invcstipaiions of the effects of foods containing copper compounds on the 

 general Jicalth and metaholism of man, J. H. Long (pp. 209^30). — The method 

 of experimenting was similar to that used in the series conducted by Taylor, 

 but the tests were continued for 4 months, made up of periods in which the 

 copper dosage was varied. The author reached the following conclusions: 



" During the lower dosage periods with copper in peas our records point to 

 nothing which may be clearly applied in showing a harmful action of the metal. 

 It appears that 100 gm. daily of peas containing 10 mg. of copper occasioned 

 no marked disturbance beyond the distaste for the peas themselves. . . . 



"About the only conclusion that we may legitimately draw from our low 

 dosage experiments is that it may be difficult to feed enough peas — and this 

 may be even more truly the case with certain other vegetables — to ingest cop- 

 per in amount sufficient to produce a harmful action, as shown by clinical and 

 metabolism observations. 



" On the other hand, it is certainly true that copper sulphate as ingested with 

 milk or beer through periods of some weeks is far from being harmless or free 

 from easily observed effects. The copper in this form has apparently a physio- 

 logical action distinct from that in the peas, and is unquestionably more 

 active. . . . 



" The addition of copper salts to peas and other vegetables has unquestion- 

 ably the effect of suggesting to the user greater freshness than may be actually 

 the case. While a very old pea may not be easily colored, it is true that peas 

 which have begun to harden, and are far from the young or fresh stage, may 

 be given enough copper materially to brighten their appearance. In this way 

 it is clear, a certain kind of inferiority is covered up. . . . 



" If, in the coppering of vegetables, an excess of the metallic salt is employed, 

 an injurious action of this copper may certainly be affirmed. This danger is 

 not a remote one, as a high copper content of cans of peas, with copper in the 

 liquor as well as in the solid, has frequently been reported. In our laboratory 

 experiments we have been able to show that an excessive amount of copper 

 may be easily added and loosely held, in some other than the ordintiry chloro- 

 phyll combination. As long as this possibility is present the whole coloring 

 process, involving the use of a heavy metallic salt, must be looked upon with 

 distrust, and must be considered as highly objectionable." 



Absorption and distribution of copper when coppered vegetables are eaten, 

 R. H. Chittenden (pp. 431-448). — In these experiments dogs and monkeys were 

 fed with coppered vegetables in order to ascertain "how far copper is absorbed 

 and to what degree it is deposited in the organs and tissues of the body when 

 taken in small doses in combination with a food such as canned peas." 



The conclusions of the author are that " when coppered vegetables are eaten 

 with the food a certain proportion of the copper is absorbed and may be tem- 

 porarily deposited in the liver. Even when taken in very small amounts, copper 

 ingested in this way is prone to be absorbed in some degree, and thus consti- 

 tutes a menace to good health. The conclusion seems obvious that vegetables 

 which have been greened with copper salts are adulterated, because they con- 



