610 



SCIENCE. 



[N. S. Vol. XXI. No. 538. 



action in those growing in filtered water. 



At first I was inclined to attribute this 

 to minute traces of copper in the flasks, 

 but subsequent experiments showed that 

 this was not the cause of the diminution of 

 the organisms. I am, therefore, inclined 

 to attribute these rather anomalous results 

 to the presence of extremely small quanti- 

 ties of copper dissolved by the water in its 

 necessarily slow passage through the copper 

 spigot to which the filter was attached. 



Some time ago I was asked if I thought 

 that a copper plate placed at the intake of 

 a reservoir would be effective in destroying 

 typhoid organisms. At that time I felt 

 such a result was almost too "marvelous to 

 be within the range of probability. But 

 in view of the results which I have just 

 given it seems that copper exerts a marked 

 oligodynamic action on typhoid and other 

 intestinal organisms, although this action is 

 not so marked as in the ease of algfe and 

 some of the saprophytic fungi. 



It is extremely fortunate that in the cop- 

 per treatment of water, a method has been 

 devised which is so effective in destroying 

 intestinal microorganisms and which can 

 be applied so easily on a large scale and so 

 safely even in the average household. Of 

 course the proper place to purify the water 

 supply of a city is in the reservoirs, before 

 the water reaches the consumer, as thus the 

 distribution of organisms like typhoid is 

 brought within the narrowest limit, and 

 individual carelessness in the community is 

 overcome. 



In a city like Philadelphia, which de- 

 pends for its water supply upon a river 

 which has tributaries in the coal region and 

 subject to contamination of all kinds, in- 

 eluding sewage and waste products from 

 manufacturing establishments, it is, of 

 course, very necessary that the water be 

 freed from gross impurities by sedimenta- 

 tion and filtration. 



At time of freshets the amount of sus'- 



pended matter may be as much as 500 parts 

 per million and it is not unusual to see a 

 statement like the following in the daily 

 papers : 



Philadelphia is to receive another dose of the 

 inky water from the coal regions of Pennsylvania. 

 Already the water is of a yellowish-red color, and 

 by to-morrow the coal dust residue- is expected. 

 The rains in the Schuylkill valley are responsible, 

 the deposits from the culm piles about the mines 

 being washed into the tributaries of the Schuyl- 

 kill River and into the main stream as well. 



But even in Philadelphia, where the 

 necessity for a filtration system is so urgent, 

 there are times when the application of a 

 method like the one proposed by Dr. I\Ioore 

 would be highly advantageous. I may cite 

 two examples in this connection: 



1. Only last September a certain section 

 of Philadelphia required 28,000,000 gallons 

 of water, and the filters for that section de- 

 livered only 22,000,000 gallons, and in or- 

 der to provide the necessary supply 6,000,- 

 000 gallons of unfiltered water were added. 

 This deliberate ' repollution ' of the water 

 supply, as it was termed by Director Mar- 

 tin, of the Department of Public Health, 

 could readily have been corrected by the 

 use of the copper method of purification. 



2. Some years ago while flushing one of 

 the large sewers, by an unfortunate acci- 

 dent there was an overflow at a point along 

 the Schuylkill River just above one of the 

 pumping stations, and as a result of this 

 contamination of the water supplied to 

 that section of the city there were 258 

 cases of typhoid fever in this section in 

 two weeks afterward, and nearly 1,500 

 eases within the next two months. 



Instances could be multiplied where the 

 copper method of purification of water 

 could be applied as an emergency method, 

 if not regularly in connection with filtra- 

 tion. , 



Even granting the efficiency of the boil- 

 ing of water for domestic purposes, I be- 

 lieve that the copper-treated water is more 



