19T 



NOTE ON THE OLIGODYNAMIC ACTION OF 

 COT'PKPv UPON CERTAIN ORGANISMS. 



]Vv \V. A. Tll.KDMAX. 



Ill coiiucctioii witli the investigatious upon copper iu 

 certaiu oysters ami upon the pollution of certain oysters 

 by sewage, and sf) possibly by disease germs, Avbicb Averc 

 discussed fully in these Reports a few years ago, it may 

 be of interest to put on record now the recent remarkable 

 results that have been obtained in America, and else- 

 where, in destroying intestinal bacteria by means of 

 exceedingly minute traces of metallic copper. 



The botanist C. von Niigeli seems first to ha\c 

 observed, some time in the eighties, that even the copper 

 dissolved by distilled water during its passage through the 

 cop])er stil] might have a toxic effect upon certain plants. 

 il(> then ex[)eriniented witli water in which copper coins 

 liad been placed, and det(U'mined, for example, that one 

 ])art of copper in about a thousand million parts of water 

 is ])oisonous to some species of tlie watei' plant Spirogyra. 

 Oiliei investigators, both in (lei'many and the United 

 States, have since exten(kHi llic experiment to the action 

 of copper ujion bacteria and iijion protozoa. They used 

 copper foil in the water, and found that /iarl/lits tyjilii 

 was es[)ecia]ly sensitive, and Ihal at a temperature of 

 '•\'y'^ to 40° V. the toxic eftect was manifested in one hour. 

 Pharmacohtgists as well as l>iologists have recognised the 

 inipnj-tancc of tliese facts, and ihcir possible application 

 to the treatment of disease. ( 'opper, whih' being 

 exceedingly toxic to micro-organisms and certain 

 parasites, is comparatively harmless to man. Professor 

 Cushiug flsyD) says: — " CViiipfM; thus seems to have a very 



