Cuap. VIL PHOSPHATE OF AMMONIA. 155 
with the point of a needle on the secretion surrounding several 
glands. These poured forth much secretion, were blackened, 
and ultimately died; but the tentacles moved only slightly. 
The dose, small as it was, evidently was too great, and the 
result was the same as with particles of the carbonate of 
ammonia. 
Half-minims of a solution of one part to 487 of water were 
placed on the discs of three leaves and acted most energetically, 
causing the tentacles of one to be inflected in 15 m., and 
the blades of all three to be much curved inwards in 2 hrs. 
15m. Similar drops of a solution of one part to 1312 of water, 
(1 gr. to 8 0z.) were then placed on the discs of five leaves, 
so that each received the z2y5 of a grain (0225 mg.). After 
8 hrs. the tentacles of four of them were considerably inflected, 
and after 24 hrs. the blades of three. After 48 hrs. all five 
were almost fully re-expanded. I may mention with respect 
to one of these leaves, that a drop of water had been left 
during the previous 24 hrs. on its disc, but produced no effect ; 
and that this was hardly dry when the solution was added. 
Similar drops of a solution of one part to 1750 of water (1 gr. 
to 4 oz.) were next placcd on the discs of six leaves; so that 
each received gy of a grain (0169 mg.); after 8 hrs. three of 
them had many tentacles and their blades inflected; two others 
had only a few tentacles slightly inflected, and the sixth was 
not at all affected. After 24 hrs. most of the leaves had a few 
more tentacles inflected, but one had begun to re-expand. We 
thus see that with the more sensitive leaves the A;5 of a grain, 
absorbed by the central glands, is enough to make many of the 
exterior tentacles and the blades bend, whereas the z)5, of a 
grain of the carbonate similarly given produced no effect; and 
aeso Of a grain of the nitrate was only just sufficient to produce 
a well-marked effect. 
A minute drop, about equal to 4, of a minim, of a solution of 
one part of the phosphate to 875 of water, was applied to the 
secretion on three glands, each of which thus received only 
srivo of a grain (00112 mg.), and all three tentacles became 
inflected. Similar ‘drops of a solution of one part to 1312 of 
water (1 gr. to 3 oz.) were now tried on three leaves; a drop 
being applied to four glands on the same leaf. On the first 
leaf, thfee of the tentacles became slightly inflected in 6 m., and 
re-expanded after 8 hrs. 45m. On the second, two tentacles 
became sub-inflected in 12m. And on the third all four ten- 
tacles were decidedly inflected in 12 m.; they remained so for 
8 hrs. 20 m., but by the next morning were fully re-expanded. 
