the T r (inspiration- Current . 4 1 3 
and, keeping the one part which retains the paraffined ex- 
tremity in water, insert the extremity of the other through 
a cork into a dry vessel, the latter will flag much the more 
rapidly. Still more direct is the following: a paraffin-injected 
branch of Tilia europaea with nine leaves was put standing, 
from 4.15 p.m. May nth till noon on the 12th, in a vessel of 
water which had been carefully weighed and so closely corked 
round the stem as to preclude possibility of loss by evapora- 
tion at Its surface. In this period of nearly twenty hours the 
branch drew up 1*005 grammes of water. This same flagged 
branch, now put out into breeze and intermittent sunshine 
from noon till 3.30 p.m., drew up 0*161 grammes. 
Again of two paraffin-injected Lime-branches, one just 
scraped to free the surface and placed in water, the other left 
closed with its cap of solid paraffin ; the latter flagged much 
more quickly, although it bore a smaller number of leaves. 
In two days the latter was, indeed, dry and shrivelled, while the 
former had preserved much of the freshness of its leaves. 
Bearing on this same point — the partial passage of 
water through the walls— -the following experiments were 
next carried out, in which it was sought to replace the 
paraffin or gelatine by a gas developed in the plant. Thus 
a cut branch first supplied from a solution of tartaric acid and 
subsequently of sodium bicarbonate will have carbon dioxide 
evolved in the lumina of its conducting tissues in consequence 
of the reaction of the salts. 
A preliminary experiment upon a Lime-branch ( Tilia 
europaea ) which had stood for two hours in a solution of 
tartaric acid and then one hour in sodium bicarbonate, before 
finally being transferred to pure water, showed rapid flagging 
of its leaves and soft shoots as the result. But as this was 
possibly a direct consequence of the action of the salts and 
not of the evolved gas, a more careful experiment was carried 
out upon five branches of Elm cut from the same tree with 
similar precautions and as far as possible of like dimensions. 
A and B were placed in sodium bicarbonate solution. 
C and D were placed in tartaric acid solution. 
Gg 
