April 21, 1905.] 



SCIENCE. 



623 



which may be used in demonstrating its 

 universal distribution as well as its innocu- 

 ousness to man. It is a well-known fact, 

 of course, that a great many analyses have 

 shown copper present in the body as high 

 as forty to fifty parts per million. In the 

 flesh of other animals, in milk and eggs, 

 copper has been detected in varying quan- 

 tities a number of times. 



Finally, the reversal of the opinion of 

 those who have such matters in charge in 

 other countries is worthy of notice. The 

 Italian government now allows 100 mg. per 

 kilo in preserved vegetables and the follow- 

 ing letter from the Pi-efecture of Police 

 shows the change in position of the French 

 Government : 



Up to the year 1899 the subject of the possible 

 bad effects on the health of the people by the 

 introduction of sulphate of copper in the prepara- 

 tion of preserved vegetables had not been so much 

 studied as it has of late, the scientific opinion 

 being divided. But since that time the consult- 

 ing committee has been renewed, and has again 

 taken up the question and passed on the experi- 

 ments made by private parties both as to the 

 quantity of copper that the human body can con- 

 sume without danger to health, and the proportion 

 that the various preserved foods that are colored 

 green may contain. From these experiments they 

 came to the conclusion that there was no longer 

 any reason to oppose the system of greening pre- 

 served vegetables by means of the salts of copper. 



Consequently it is now allowable in 

 France to use salts of copper for preserving 

 the green color in food products in any 

 amount, although until the harmlessness of 

 this metal became known it was forbidden 

 to even use a copper vessel for preserving 

 purposes. 



After all, the question is not a new one 

 in this country, the introduction of Bor- 

 deaux mixture as a fungicide some years 

 ago necessitating the fighting over of the 

 whole subject of the effect of copper upon 

 man. At that time one board of health 

 ordered tons of grapes that had been treat- 

 ed with Bordeaux mixture to be dumped 



into the water, and it was not until Dr. 

 Galloway and others connected with the 

 Department of Agriculture at that time, 

 showed how impossible it was to do any 

 injury with this solution that the popular 

 prejudice began to die out. Nowadays no 

 one thinks anything about whether the 

 fruit he is eating has been treated with 

 copper or not. 



The objections to the use of copper sul- 

 phate, because careless or igTiorant people 

 in charge of water supplies might add too 

 much, hardly seems to require an answer. 

 Since there would be no difficulty in tasting 

 the copper long before an amount sufficient 

 to cause inconvenience could be consumed, 

 and since by the addition of lime we can 

 almost immediately eliminate any excess of 

 copper, it would seem that we had as many 

 safeguards for this method as for any which 

 could ever be introduced. Certainly, the 

 danger of mismanagement and fatal error 

 is nothing like so great as for sand filtra- 

 tion. It might be a good plan to encourage 

 any method that would emphasize in any 

 way the importance of putting the public 

 water supplies of this country into the most 

 competent hands possible. That the public 

 is unable to detect failures in filtration 

 plants until the death rate begins to rise, 

 might be urged against this system of 

 water purification. Certainly it is time we 

 realized that filtration is one of the most 

 delicate operations in sanitary science and 

 that neglect or ignorance is constantly 

 causing a reduction in the efficiency of this 

 method. The man who makes public the 

 eases of adding unfiltered to filtered water, 

 the running of filters at too high a rate, the 

 leaks in basins, conduits, etc., and the many 

 other defects which are constantly occur- 

 ring with this method may appear to be an 

 enemy of sand filtration. In reality he 

 would probably do more to compel authori- 

 ties to raise this method to the efficient 

 place it ought to have, but does not occupy 



