70 DROSERA ROTUNDIFOLIA. [CHar. V 
About: the same quantity of chopped cabbage leaves and of distilled 
water-as in the last experiment, were kept in a vessel for 20 hrs. ina 
hot closet, but not heated to near the boiling point. Drops of this 
infusion were placed on four leaves. One of these, after 23 hrs., was 
much inflected ; a second slightly; a third had only the submarginal 
tentacles inflected ; and the fourth was not at all affected. The power 
of this infusion is therefore very much less than that of the decoction ; 
and it is clear that, the immersion of cabbage leaves for an hour in 
water at the boiling temperature is much more efficient in extracting 
matter which excites Drosera than immersion during many hours in 
warm water. Perhaps the contents of the cells are protected (as 
Schiff remarks with respect to legumin) by the walls being formed of 
cellulose, and that until these are ruptured by boiling-water, but little 
of the contained albuminous matter is dissolved. We know from, 
the strong odour of cooked cabbage leaves that boiling-water produces 
some chemical change in them, and that they are thus rendered far 
more digestible and nutritious to man. It is therefore an interesting 
fact that water at this temperature extracts matter from them which 
excites Drosera to an extraordinary degree. 
Grasses contain far less nitrogenous ‘matter than do peas or cabbages. 
The leaves and stalks of three.common kinds were chopped and boiled 
for some time in distilled water. Drops of. this decoction (after having 
stood for 24 hrs.) were placed on six leaves, and acted in a rather 
peculiar manner, of which other instances will be given in the seventh 
chapter on the salts of ammonia. After, 2 hrs. 30.m. four, of the 
leaves had their blades greatly inflected, but not their exterior, tentacle ; : 
and so it was with.all,six, leaves after 24 hrs.. Two, days afterwards 
the blades, as well as the few submarginal' tentacles whi ch, had beep 
inflected, all re-expanded; and much of the fluid on their discs was by this 
time absorbed. It appears:that the decoction strongly excites the glands 
on the disc, causing the blade to be quickly and greatly inflected ; but 
that the stimulus, differently from what occurs in ordinary cases, “does 
not spread, or only in a feeble degree, to the exterior. tentacles. |, 
I may here add that one part: ‘of the extract, of ‘belladonna, (procured 
from a druggist) was dissolved, in 437 of water, and: drops, were placed 
on six leaves. Next day all. six were somewhat inflected, and after 
48 hrs. were completely re- expanded. , It jwas . not the ‘included 
atropine which produced . this., effect, for. I. ‘subsequently, ascertained 
that it is quite powerless. I also procured some extract of hyoscyamus 
from three shops, and made infusions of the same strength as before. 
Of these three infusions, ‘only one acted on’ some of ‘the leaves, which 
were tried. Though.druggists believe that all the albumen is precipi- 
tated in the preparation of these drugs, I cannot doubt that some is 
occasionally retdined ; and a trace would be ‘sufficient to excite the 
more sensitive leaves of Drosera. 
