1056 FOODS AND FOOD ADULTERANTS. 



once more appealed to the long-suffering Coraite consultatif d'hygiene 

 relative to the copper question, transmitting copies of the report of 

 Pasteur and Brouardel to the Conseil d'hygiene et de la salubrite de 

 la Seine, and asking for an expression of opinion on it. He inclosed, 

 further, a letter from the prefect of police to the same general purport. 

 A commission consisting of Wurtz, Gallard, Girard, Brouardel, Chatin, 

 and Eochard was appointed to deliberate on the subject. It was to 

 consider whether it were possible to can leguminous vegetables, pro- 

 ducing a salable article, without use of copper salts ; in what propor- 

 tion copper salts were found in commercial goods and in what shape; 

 and, lastly, if such quantities were dangerous to health. It reported, 

 by Gallard, somewhat as follows : l 



Legumes preserved by Appert's process take a color disagreeable to the eye, and 

 in spite of their excellent quality are not liked in commerce. Greening artificially 

 is almost a necessity. 



There are in Paris two canneries which impart to their goods a beautiful green 

 color without the aid of copper. In one of these greening is done with chlorophyl 

 extracted from spinach. In the other the natural green of the peas is retained by 

 a complicated process involving the use of lime sucrate, salt, soda, and sulphite of 

 sodium. Analyses of samples from both factories were made, but in neither case 

 was copper found. 



One of the largest .of the Parisian canneries employing the copper process was 

 visited. In this establishment 45 grams of copper sulphate are used with every 45 

 liters of small peas. The resulting peas on examination gave 270 mg of copper per 

 kilo. From this it was calculated that 41.550 grams of the copper sulphate originally 

 employed were absorbed by the peas and 3.450 grams remained dissolved in the water 

 (120 liters) of the coppering bath. 



Copper in this great quantity was not found in other goods furnished by this fac- 

 tory. In these the copper descended to 170 or 180 mg, averaging about 175. Anal- 

 yses of preserves from other factories gave approximately the same figures, being 

 in one case 180 mg and in another 195. In these analyses (Chatin) the copper pres- 

 ent in the peas alone was estimated, the surrounding liquor being poured off prior 

 to the analysis. Other analyses, giving the copper present in the total contents of 

 the can (Wurtz), gave 45 to 60 mg of copper. Even after calculating for the water 

 there is a difference between the two sets of figures. 



It is claimed that a very small quantity of copper (15 to 20 mg per kilo) is amply 

 sufficient to give the desired hue. It is also said that quantities of copper very 

 much in excess of that necessary to color properly would give an objectionable 

 flavor. Leguminous preserves containing 195 and 270 mg of copper per kilo do not 

 betray it to the taste. Not only is it a fact that the copper in vegetables artificially 

 greened can pass the limit prescribed, but it is a fact that it usually does. It would 

 be interesting to determine by actual experiment just what degree of saturation is 

 possible and how the limit varies with the different vegetables. 



As to the nature of the compounds of copper contained in artificially greened veg- 

 etables this is a matter of secondary importance. They are principally insoluble 

 albuminates, capable of being changed in the digestive process into soluble salts, 

 readily absorbed. 



Copper is not a cumulative poison like lead, and is not violently poisonous even 

 in largo doses, its action causing vomiting, colic and possibly diarrhea of a mild 

 type. There is great doubt as to whether death has ever brcn caused liy copper 

 poisoning. This, however, does not appear sufficient ground to the majority of the 



'Recueil des trav. du Comite" conanltfttif d'hygirn publiquo, 1881, 11, 362, 



