Bitter Fit in Apj^les. 369 



pareil and Five Crown. Owing to the exhaustion of the supply be- 

 fore the experiments were completed, a small number of purchased 

 apples were also used, mainly of Five Crown. These were care- 

 fully cleaned and wiped in all cases to remove any poison that 

 might be adhering to the skin. The purest obtainable salts 

 were used, and supplies of specially pure distilled water were 

 obtained from the Chemical and Physiological Schools. The Minis- 

 ter for Customs (Mr. Tudor) kindly consented to have chemical 

 analyses made by the Federal Analyst (Mr. P. Wilkinson), of 

 the apples used in order to determine the amount of poison 

 necessary to produce artificial bitter pit, and various other 

 points connected with this question. Mr. Wilkinson's aid has 

 been extremely ' valuable, and has been most zealously and 

 ungrudgingly given. 



The first tests were made with sound, uninjured apples by 

 immersing them in solutions of mercuric chloride, copper sul- 

 phate and lead nitrate of varying strengths. In all concen- 

 trations of less than 1 in 1000, a litre of solution was used to 

 each apple. 



Copper Suljjhate. — Jonathans in solution for one week, and 

 air one week. 



One gram per 200 c.c. Large and small pits from 1 cm. to a 

 mm. diameter, and extending about half their diameter into 

 the pulp. On submitting the material to the Federal Analyst he 

 reported '' No copper detected." In all cases the apples were 

 well washed in running water to remove any poison adhering to 

 iTie surface before forwarding them for analysis. 



One per 1000. Pits smaller and less numerous. 



One per 5000. None of pits exceeding 3 mm. diameter, and 

 1-2 mm. depth. 



One per 25,000. Minute superficial spots none exceeding 1 

 mm. depth. 



One per 100,000. No perceptible effect. 



Apples in distilled water one week, and in air one week. Len- 

 ticels slightly more prominent in some cases, no other effect. 



Lead Nitrate. — Jonathans, 



In 1 gram per 100 cc. 1 day. After 2 weeks in air, small 

 ^ell-defined pits 2-4 mm. diameter, and 1 to 3 mm. deep. Tlie 

 federal Analyst reported '' No lead detected." 



