i 9 o 5 ] 



ON INTESTINAL ORGANISMS. 55 



the time required was 24 hours as against 8 minutes in the first 

 instance. 



While we have seen that solutions containing minute quantities 

 of copper are exceedingly toxic to certain organisms, other investi- 

 gators have shown that various plants not only withstand the influ- 

 ence of relatively large quantities of copper sulphate, but under 

 certain conditions even appear to be benefited by its presence. 

 With these various data before us we may say that while copper 

 has a specific toxic action even in very minute quantities on certain 

 organisms, it should be borne in mind that these same organisms 

 manifest a specific sensitiveness towards copper and various other 

 metals. 1 



These data are not only of great interest from a scientific point 

 of view but in their practical application are of very great impor- 

 tance, and it was to be expected that pharmacologists would appre- 

 ciate the important bearing of this line of investigation on their 

 work. Cushny 5 among pharmacologists early recognized the value 

 of these researches and the possibilities in their application in the 

 prevention and treatment of disease. He states that while copper 

 is comparatively harmless to man, yet it is exceedingly toxic to 

 certain microorganisms and intestinal parasites. He says : 



" Small quantities of copper may be taken for indefinite periods 

 without any symptoms being induced, so that so far as man is con- 

 cerned the general action of copper is unknown. ... On the 

 other hand, copper is a deadly poison to several of the lower plants. 

 Thus, traces of copper added to the water in which they live, 

 destroy some of the simpler algae, and Nageli asserts that 1 part 



1 While various explanations might be offered to show why such extremely 

 minute quantities of copper in solution are sufficient to kill unicellular and fila- 

 mentous algre, bacteria, and unicellular animal organisms, and yet not affect 

 multicellular plants and animals, whose cells are as delicate in structure as those 

 of the unicellular organisms, it seems that this is in a measure due to the fact that 

 in the latter the entire individual is comprised in a single cell, which performs all 

 the vegetative as well as reproductive functions, and being entirely surrounded by 

 the copper solution, all the life process are affected, there being no way for the 

 organism to distribute the solution to other cells, and thus by a dilution minimize 

 the toxic action of the copper. Or if some of the cells in the multicellular organism 

 are destroyed or injured by exposure to the solution, others are formed to take their 

 place from the more or less deep-seated meristematic cells. It is true that the 

 idiosyncrasies in these organisms should also be borne in mind, some of them 

 being more resistant than others. 



