22 METHOD OF DESTROYING ALG.E IN WATER SUPPLIES. 



single instance was given of injury to health resulting from the daily 

 absorption of a small quantity of copper. On the other hand, many 

 instances were cited where foods containing copper in considerable 

 amounts were used without producing any harmful effect whatever. 

 It should be noted also that the law prohibiting the use of copper in 

 regreening fruits was repealed by the French authorities after the dis- 

 cussion before the Belgian Academy. 



According to Thiemann-Gartner, ff chronic copper poisoning has 

 never been proved. The supposed copper colic was discussed by 

 Burcq & before the Congres Internationale d'Hygiene in 1878, and 

 declared by him to have no existence; he even went so far as to assert 

 an immunity against cholera for the workers in copper during various 

 epidemics at Paris, Toulon, Marseilles, and elsewhere, but this state- 

 ment he afterwards modified with reference to the epidemic of 1832. 

 The good health of copper workers is also noted by Houles and 

 Pietra-Santa, c though they do not claim for them immunity from 

 typhoid and cholera. Gautier^ states that persons working in dye 

 factories, where the hands, faces, and even hair were colored green by 

 copper, were pl^sically unaffected, which is true also of copper 

 turners, who remain apparently in the best of health although con- 

 stantly in an atmosphere highly charged with copper dust. 



A considerable number of experiments have been made to determine 

 the effect of copper upon man when taken into the intestinal tract. 

 For fourteen months Galippe e and his family used food cooked and 

 cooled in copper vessels, the amount of copper present in the food 

 being sufficient to be easily determined. Robert's experiments^ show 

 that a 60-kg. man can take 1 gram of copper per day with perfect safety. 

 From his own results Lehmann^ considers that copper to the amount 

 of 0.1 gram in vegetables may produce bad taste, nausea, possibly 

 colic and diarrhea, but nothing more serious. He has himself found 

 peas containing as much as 630 mg. of copper per kilogram not dis- 

 tasteful, and 200 mg. consumed at a single meal was without effect. 

 A very careful and thorough series of tests have shown that some 

 individuals, at least, can take copper even to the amount of 400 to 

 500 mg. daily for weeks without detriment to their health. 



Tschirsch^ finds that 0.01 to 0.02 of copper (0.039 to 0.078 of copper 

 sulphate) in dilute form have no effect; 0.05 to 0.2 causes only vomit- 

 ing and diarrhea. 



Thiemann-Gartner, Handbuch und Beurtheilung der Untersuchung der Wasser, 

 Braunschweig, 1895. 



&Burcq, Congres Internationale d' Hygiene, 1: 529, 1878. 



Houles and Pietra-Santa, Journal de Pharmacie et Chimie, 5th Ser., 9: 303. 



d Gautier, Le Cuivre et le Plomb, Paris. 1883. 



e Galippe, Compt. Rend., 84: 718. 



/Kobert, Lehrbuoh der Intoxicationen. (Original not consulted.) 



<7Lehmann, Munch. Med. Wochensch., 38: 603. 



'' Tschirsch, 1. c. 



