22 



Alfred J. Eivart 



sap. since alGohol is one of those yubstances which are freely per- 

 meable to the protoplasmic membrane. * 



For the tests pure absolute alcohol was used, prepared Yates' 

 Pippin apples being immersed for four days in the solution and 

 eiamined after three days in air. The temperature averaged 14^16 

 d 



(leg. u. 



1 i-.c. of absolute al<ohol per 

 lOc.e. of mixture. (100 c.c. 

 of sohitiou). 



1 c.c. of absolute alcohol per 

 100 c.c. of luixtui-e. (1000 

 c.c. of sohition). 



I c.c. of absolute alcohol per 

 1000 c.c. of mixture. 

 (1000 c.c. of solution). 



1 c.c. of absolute alcohol per 

 10,(X)0 c.c. of mixture. 

 (1000 c.c. of sokxtion). 



From superficial browning to pits 1-2 mm. 

 diameter and depth. 



From superficial browning to pits 1-2 mm, 

 diameter and depth. 



No signs of poisoning. 



No signs of poisoning. 



Hence in its poisonous action on the pulp cells of apples, alcohol 

 comes next to pure water, and is one of the least poisonous of all 

 the substances tested. 



Tannic acid or Gallo-tannic acid is present in the pulp both of 

 ripe and unripe apples, and Mr. P. R. Scott's analyses give the 

 ajnount as usually less tiian 0.1 gram per cent., and as being slightly 

 more abundant in pitted than in normal apples. 



Yates' Pippin prepared. After seven days' immersal at 1-3 — 16 

 deg. ('.. in tannic acid solutions in water. 



1 gram per 100 c.c. 

 1 gram per 1000 c.c. 

 1 gram per 10,000 c.c. 

 1 gram per 100,000 c.c. 

 1 gram per 1()(K),(K>() c.c 



Brown pits 1-2 mm. diameter and depth. 

 Brown pits 0.5-1 mm. depth. 1-2 mm. diameter. 

 No distinct signs of poisoning. 

 No signs of poisoning. 

 No signs of poisoning. 



Sturmer Pii){>in a])ples were sensitive to tannic acid in ten times 

 greater dilution as compared with Yates' Pippin. 



Tannic aiid. thei'cfore, comes next to aleolml in tlie feelilcness of 

 its pdisoiidus action, and is less jyoisonous tlian many nutrient 

 salts are when applied singly. It may safely be assumed therefore 

 tliat tbe slight differences in the pi-rcentage of tannic acid sup- 

 posed to exist between pitted and clean apples have no causative 

 relationship with l)itter pit. 



