' Bitter Fit in A'lypie^. 'Z7- 



cutf clii'iiiical analysis. MfAlpiiif (p. 70 of Keportj dismisses 

 the poisoning theory of bitter i)it in five lines as follows : " Tliis 

 theory is sufiieiently disposed of by the analysis of pitted 

 apples made by Mr. P. K. Seott, Clieniist for Agrieulture. A 

 Stsite Committee was appointed t(j collect pitted apples from un- 

 sprayed orchards, and on analysis, not the slightest trace could be 

 foinnl of either lead or arsenic, or any other mineral poison." 

 Apart from the fact that the quantity of pitted apples from un- 

 spiayed oichards which this Committee, of which I was a member, 

 was able to obtain was exceedingly small, and quite insufficient 

 for an exhaustive examination of the delicacy needed, no attempt 

 was made to detect mineral poisons in geneial. Mr. Scott practic- 

 ally confined his tests to the detection of arsenic. The only other 

 test used was as follows. " Another portion of the dried material 

 was incinerated at a low heat, and the ash dissolved in hydrochlorie 

 acid, and a current of sulphuretted hydrogen was passed through 

 the solution. I did not obtain any coloration of liquid or precipi- 

 tate by sulphuretted hydrogen."' McAlpine is evidently unawaie 

 that this method would fail entirely to detect manganese, cobalt, 

 nickel, zinc, ahmiinium. iron, or cliromium. Further it would be- 

 entirely useless to attempt to detect lead, mercury, silver, gold ,or 

 copper by this method when present in dilutions just within the 

 toxic limit to the pulp cells of adidt apples, without using very 

 large quantities of material and special methods of extraction and 

 mechanical or electrolytic concentration. 



Only one experiment is given with a metallic jKiison — (Report 

 p. 23) — and as an adult apple was used, in which the starch had 

 all or practically all dissolved, little or no starch could be expected 

 to be present in the dead tissue. A saturated solution of mercuric 

 chloride in alcoliol was used, which latter is able to kill the pulp 

 cells by merely drsiwing water from them, and also interferes with 

 the absorption of the mercuric chloride by the pulp. As the 

 solution used had a concentration of 1,000.000,000 times above 

 the toxic limit for Yates' Pippins, it is not surprising that some 

 effects were produced. 



In regard to the difficulty raised as to how poisons could be 

 absorbed from the soil by the delicate root-hairs, and the state- 

 ment that "the concentration within the cells must, become more 

 or less ecjualised with that without, before the plant can be 

 ]properly nourished." (p. 27. of Report), every student of plant 

 physiology knows that the latter statement is quite misleading. 

 It is also well known that the roots of various plants can absorb 

 traces of various mineral poisons, which may accumulate in special 



