294 Transactions of the Canadian Institute. [Vol. VII. 



Glycerine m/2, all fresh, Nicotiana spotted. 



Gr. sugar m/2, all fresh. 



Ca. sugar m/2, all fresh. 



MgCL m/2, similar to KCl. 



NaCl m/2, similar to that of KCl. 



It was found that in ten to twelve hours after taking the leaves from 

 the solutions some of them underwent other changes worthy of note. 

 The part of the blade of the leaf turned yellowish-brown by the acids 

 had changed to a bluish colour, showing that very probabl}' the tissue was 

 undergoing further changes, resulting in a product having an alkaline 

 reaction. 



Judging from their effects, these substances may be classified as 

 follows : — 



Acids HCl, H„SO,. 



Alkalies KOH, NaOH. 



Decomposable alkalies Na.XOg, NH^OH. 



Poisons CuSO^, HgCl„, PbA^, FeSO,, ZnSO^. 



Osmotically active substances.. MgClo, KCl, NH^NOg, etc. 



In a second series of experiments the arrangement was as shown in 

 Fig. 8, and continued for three days, when the leaves were taken from 

 the solutions, and observations made upon their conditions then and 

 afterwards. The acids, in a measure, acted as did the alkalies, showing 

 that the.se substances alike penetrate readily the walls of the cells in 

 all directions, and do not follow the veins. Acids and alkalies to some 

 extent dissolve the cellulose, and so make a way for themselves readily 

 in all directions. 



LEAF OF PRIMULA STELLATA, PLACED AS IN FIG. 



L 



Strength of Solution, »iJ4 ; set tip November gth. 



