So 



position of the clilorophyll,, and all its globules Mere fused 

 into one or two large masses. 



"A solution of opium in water acts similarly to prussic 

 acid, but a longer time is necessary for the agent to operate, 

 and for the plant to recover. i V 



" The effects of these two tests on the chara is similar to 

 that on the valisneria. Acetate of lead, and oxymuriate of 

 mercury in water, irreparably destroy the circulation. 



" Spirit of wine, or alcohol in solution, arrests the motion 

 with greater or less rapidity, according to its state of dilution ; 

 if the solution be very weak, and the leaf be immersed in 

 pure water as soon as the stoppage becomes apparent, the cir- 

 culation will revive again after the lapse of two or three 

 hours. 



"Liquor potassse, soda and other alkalies, acetic and other 

 acids, produce stagnation in a short time, and no recovery can 

 be effected. 



"A small slip of valisneria, in which no circulation was 

 seen to be going forwards, was cut off a growing leaf, and 

 placed between two pieces of blotting paper, to remove all 

 superfluous moisture. It was then immersed in olive oil, in 

 two minutes circulation had begun ; in an hour it was general, 

 and it continued for the next 36 hours. 



" Another sbp from the same leaf was placed in a weak 

 solution of sugar, and presented the same results. 



" Another similar slip was placed in a strong solution of 

 sugar, the motions being very brisk at the time ; at first no 

 effect was produced, but after a time, each cell was found to 

 be more or less filled with a transparent fluid, \vhich dimi- 

 nished the space for circulation considerably ; the motion, 

 however, still went on, though no longer round the cell wall, 

 and was not stopped until the invasion of the new material 

 bad forced the whole of the green globules into one single 

 mass." 



In addition to these experiments, the author recorded an 



V 



