372 Alfred J. Ewart : 



followed, from comparative trials with known quantities, would 

 enable the presence of approximately 1-10, 000th of a grain of 

 mercury to be detected," 



The waxy bloom was removed from a further set of 15 

 Jonathans which were immersed for a week in a half per cent, 

 solution of mercuric chloride, allowing them to float and aerate 

 themselves for one hour daily. The apples all had sound, unbroken 

 skins, large stalks and well-closed calyces. They were covered 

 with large dead brown patches, extending in some cases nearly 

 to the core, and there was evidently a slight penetration at the 

 calyx end, and still more at the stalk end of the fruit. Hence 

 after thorough washing, a one centimetre cylinder of the core 

 was removed, and the remainder forwarded for analysis. 



The report from the Federal Analyst was as follows : — " The 

 fifteen samples of apples referred to in the attached letter from 

 Professor Ewart have been examined as to the presence of mer- 

 cury compounds as detailed hereunder : — 



A. Mercury on the exterior surface of the apples 



(as removed by chlorine and washing) cal- 

 culated as mercuric chloride 17 mg. 



B. Mercury contained in thin peelings, calculated 



as mercuric chloride 20 „ 



C. Mercury contained in brown pit pulp, outer 



layers, calc. as mercuric chloride 16 ,, 



D. Mercury contained in deeper layers of pit pulp, 



calc. as mercuric chloride 18 ,, 



" The quantities of mercury reported are probably, owing to 

 imperfections in method of determination, slightly below the 

 amounts actually present in the apples." 



In this experiment the total volume of the solution was 2000 

 CO. and of the apples 2760 c.c. The weight of mercuric chloride 

 in the solution was 10 grams, and the weight of mercury found 

 in the apples 71 milligrams, representing 96 milligrams actually 

 absorbed of the chloride, or rather more than this allowing for 

 losses in analysis. Hence the concentration in the apples after 

 a week's immersal did not exceed 1-lOOth of that of the solu- 

 tion outside. 



An exactly similar experiment was performed with 12 wiped 

 Jonathan apples, but the calyx and stalk were covered with 



