96 OTTO GLASER. 



Test Ci X Pi Micrograms Cu. 



D2 per c.c. Eggs. 



I.. 10 X -S 



2.00 



1 10 X .5 



1.96 



1 10 x .5 



2.03 



20.83 



21.25 



20.50 



Average = 20.86 /igv. 



The copper content of the fertilized ovum apparently has the 

 general order of magnitude characteristic of the unshed ovarian 

 egg. That of the shed egg is, roughly, from eight to ten times 

 greater. 



XII. Discussion. 



1. The Copper Problem. 



Unless bound up in respiratory or other pigments, copper is con- 

 sidered essentially a poison. Its use in germicides and fungicidal 

 solutions, the harmful influences on higher and lower plants, power 

 to block organic catalysis, the medicinal properties of colloidal 

 suspensions and copper salves — all support the prevalent view. 

 Yet- there are no poisons in nature ; there are only poisonous 

 effects. These may be exercised by the commonest articles of diet 

 at certain concentrations and by copper, it happens, at very low 

 ones. 



Even a cursory examination of the literature suggests further 

 misgivings. Copper has been found repeatedly in three of the five 

 main divisions of the plant kingdom and among animals, with 

 equal frequency, in nine phyla, ranging from protozoa — if Volvox 

 ('2 1 6 ) is an animal — to man. However, only Maquenne and 

 Demoussy ('20 s ), who worked on plants, and Rose and Bodansky 

 C20 1 ), whose studies cover a wide range of marine animals, are 

 actually bold enough to suggest that copper in general may be more 

 than an adventitious element which living things somehow tolerate. 



Specific processes in which it normally plays a role are still 

 unknown; moreover, they are quite likely to remain so unless we 

 free ourselves for investigation by an admission of ignorance. 



As a matter of fact, copper has many of the qualifications of a 



