844 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. 



valuable storage tank for all purposes that we possess." 

 Finally, Kraemar lias, during the last year, carried out a 

 series of most elaborate and interesting experiments in the 

 Philadelphia College of Pharmacy, " with a view of 

 testing the efficiency of metallic copper for destroying 

 typhoid and colon bacilli in water." He writes as 

 follows : — 



" From the experiments thus far conducted, as well 

 as the results obtained by other writers, the following 

 conclusions may be drawn : 



" 1. Certain intestinal bacteria like colon and 

 typhoid are completely destroyed by placing clean 

 copper foil in water containing them, or by adding the 

 organisms to water previously in contact with copper 

 foil. 



" 2. The toxicity of water in which either copper 

 coins or copper foil has been added is probably due to 

 a solution of some salt of copper, as first suggested by 

 Nageli. 



" 3. The copper is probably in the form of a 

 crystalloid rather than that of a colloid, as it has the 

 property of permeating the cell walls and organised cell 

 contents of both animals and plants, thereby producing 

 the toxic effects. 



" 4. While the effects produced by the oligo- 

 dynamic action of copper are apparently different from 

 those of true chemical poisons, the difference is 

 probably in degree only, and not in kind. 



" 5. Certain lower organisms, including both 

 plants and animals, possess a specific sensitiveness to 

 minute quantities of copper, and it has been shown that 

 they are not restored on transferring them to water free 

 from oligodynamic properties. 



" G. Oligodynamic solutions of copper are 



