76 DROSERA ROTUNDIFOLIA. Crap. V 
CHAPTER V. 
Tue Errecrs or Non-NITROGENOUS AND NiTRocEenovus Orcanic Fiums 
oN THE LEAVES. 
? 
Non-nitrogenous fluids—Solutions of gum arabic — Sugar — Starch 
— Diluted alcohol — Olive oil—Infusion and decoction of tea — 
Nitrogenous fluids — Milk — Urine— Liquid albumen — Infusion 
of raw meat—Impure mucus — Saliva — Solution of isinglass— 
Difference in the action of these two sets of fluids — Decootion of 
green peas—Decoction and infusion of cabbage— Decoetion of 
grass leaves. 
WHEv, in 1860, I first observed Drosera, and was led to 
believe that the leaves absorbed nutritious matter from 
the insects which they captured, it seemed to me a 
good plan to make some preliminary trials with a few 
common fluids, containing and not containing nitro- 
genous matter; and the results are worth giving. 
In all the following cases a drop was allowed to fall 
from the same pointed instrument on the centre of the 
leaf; and by repeated trials one of these drops was 
ascertained to be on an average very nearly half a 
minim, or ;1,; of a fluid ounce, or ‘0295 ml. But these 
measurements obviously do not pretend to any strict 
accuracy ; moreover, the drops of the viscid fluids were 
plainly larger than those of water. Only one leaf on 
the same plant was tried, and the plants were col- 
lected from two distant localities. The experiments 
were made during August and September. In judging 
of the effects, one caution is necessary: if a drop of 
any adhesive fluid is placed on an old or feeble leaf, 
the glands of which have ceased to secrete copiously, 
the drop sometimes dries up, especially if the plant 
