408 Alfred J. Ewart : 



were 3-4 mm. deep, but with solutions from lead chromate and 

 London Purple, only a" superficial browning and a few pits not 

 exceeding- 1 mm. depth were formed. 



Sound apples with a normal skin floated for one week on clear 

 saturated solutions from arsenate of lead, lead chromate, Lon- 

 don Purple and Paris Green, allowed to stand, decanted, and 

 then filtered, showed after three weeks in air from a few to 

 numerous small superficial spots, but no pits, and the pulp was 

 wholly sound. The above tests were done with Jonathan, Yates' 

 Pippin and Scarlet Nonpareil apples. 



Evidently, therefore, all these substances are sufficiently poi- 

 sonous to poison the pulp cells when they gain entry, but are 

 unable (in solution in appreciable amount) to directly penetrate 

 the skin of a sound adult apple with a well-developed cuticle 

 and bloom. 



Bain (I.e. p. 43) found that the injurious action of Bordeaux 

 mixture and copper hydrate on peach leaves was greatly decreased 

 in the presence of free lime or calcium carbonate. Hence, the 

 influence of these substances by themselves was tried. Apples 

 floated on lime water had chalk deposited on the skin, but 

 even after one week showed no signs of injury, and the chalk 

 readily rubbed off. 



Prepared apples placed in saturated lime water for one week 

 formed shallow brown pits beneath each prepared spot on keep- 

 ing, in a 1-lOth saturated solution only a superficial browning 

 appeared, and a 1-lOOth saturated solution produced no percep- 

 tible effect. Prepared apples placed in a clear saturated 

 solution of lead arsenate, to which an equal bulk of 1-1 00th 

 saturated lime water was added, showed no signs of poisoning, or 

 only very faint superficial browning even after one week. 



It is quite clear therefore that the addition of free lime to 

 arsenate of lead diminishes its toxicity, and would probably also 

 make the same quantity go further in practice. Whether the 

 mixture would be equally effective arid firmly adherent could 

 only be determined by field trials. 



Other spraying materials. 



Apples rubbed on one side with emulsified spraying oil 

 (Emulsi-A-01), developed in one to three Aveeks several circular 



