374 Alfred J. Eivart : 



nitrate for one week, and the artificial bloom then removed by 

 wiping with a cloth and warm water. There were no signs of 

 asphyxiation in this time, in spite of the blocking of the 

 pores by paraffin, but the apples developed a slight alcoholic 

 smell. After three weeks in air, all the apples remained quite 

 sound, with no signs of any development of bitter pits superficial 

 or deep-seated. 



Apples more sensitive than other organisms. 



All the poisoned apples from these and the following experi- 

 mentsl, which were not used for analysis or microscopic exami- 

 nation, were fed to guinea pigs, and these included apples 

 soaked in half per cent, solutions of mercuric chloride and cop- 

 per sulphate, and then kept until a large part of the pulp was 

 dead and brown. The guinea pigs, beyond occasionally showing 

 thirst and micturating freely, showed no signs of poisoning, 

 but they usually refused to eat the skin and worst rotted parts 

 of the most strongly poisoned apples. In any case, in the 

 course of several months each guinea i^ig ate at least twice its 

 own bulk of poisoned apple pulp without suffering appreciably. 



In addition, wiped apples were soaked in 0.5, 0.2 and 0.1 per 

 •cent, solutions of mercuric chloride, and in 1 and 5 per cent, 

 solutions of copper sulphate for one Aveek, and then kept until 

 the surface pulp was rotted wholly or in part. The skin was then 

 broken in places and infected with the spores of the green mould, 

 Penicillium. The hyphae developed in the dead pulp nearly 

 as rapidly as in dead unpoisoned apples killed by boiling, and 

 more rapidly than in the pulp of sound apples. Spores were 

 also formed freely, mainly fr»m the broken surface of the skin. 

 From the analyses given above, the percentage of mercury in the 

 dead pulp cells could not have greatly exceeded 1 in 10,000, and 

 since Penicillium can develop well on solutions containing as 

 much as 15 per cent, of copper sulphate, it is not surprising that 

 it should be more resistant to mercury than the pulp cells 

 of the apple. Possibly its hyphae may be more or less imper- 

 meable to soluble mercury salts just as they are to copper salts, 



1 Excepting those treated with alkaloids 



