388 Alfred J. Eivart : 



One c.c. of 30 per cent, solution in 100 of water. Pits from 

 5-6 nun. deep. 



One per 1000. Pits 4-5 mm. deep. 



One per 10,000. Pits superficial to over 1 mm. deep. 



One per 100,000. No perceptible signs of poisoning. 



Apples are therefore very much less sensitive to formaldehyde 

 than might have been expected, and a relatively considerable 

 accumulation of it would be necessary to poison the pulp cells. 

 Since it is a volatile substaijce it could hardly produce a per- 

 manent arrest of ferment action on the starch grains. The same 

 objection applies to the following alkaloids, which are produced 

 by some plants, but not by apples. 



Alkaloids. 



To many plants, and more especially to those which produce 

 them, alkaloids are comparatively non - poisonous, and some 

 fungi may even use them as food. Generally speaking, the alka- 

 loids are rather nerve and muscle poisons than protoplasmic 

 poisons, and a plant which has no nerves or muscles may or may 

 not be sensitive to alkaloids, which are deadly poisonous to 

 warm-blooded animals. Strychnine appears to be the most 

 poisonous of the alkaloids to those plants which are sensitive 

 to alkaloids. In this case apples appeared to show a quite 

 unusual and unexpected general sensitivity to poisonous alkaloids. 



Brucine Xitrate.^ — 



Prepared Five Crown apples. — Three and a-half days in solu- 

 tion, examined after one week in air. 



One per 1000. Pits J to 1 cm. diameter, and 2 to 5 mm. deep. 



One per 10,000. Pits I ^^ 1 cm. diameter, and 1 to 4 mm. 

 deep. 



One per 100,000 Pits 2 to 5 mm. diameter, and 1 to 3 mm. 

 deep. 



One per 1,000,000. Pits 1 to 2 mm. diameter, and i^ to 1 mm. 

 deep. 



One per 10,000,000. No perceptible poisoning action. 



1 Brucine nitrate dissolved in very dilute HNOa and solution neutralized with NHiM( 

 If the iicid is sufficiently dilute, no brownish red colour is produced. 



