Cuar. VIL) OTHER SALTS OF AMMONIA. 137 
became strongly marked. After only 8 hrs. 30 m. the tentacles began 
to re-expand, and by the next morning, after 24 hrs., were fully 
te-expanded on four of the leaves, but still slightly inflected on two. 
General Summary and Concluding Remarks on the Salis of 
Ammonia,—We have now seen that the nine salts of ammonia 
which were tried all cause the inflection of the tentacles, 
and often of the blade of the leaf. As far as can be ascer- 
tained from the superficial trials with the last six salts, the 
citrate is the least powerful, and the phosphate certainly by 
far the most. The tartrate and chloride are remarkable from 
the short duration of their action. The relative efficiency of 
the carbonate, nitrate, and phosphate, is shown in the fol- 
lowing table by the smallest amount which suffices to cause 
the inflection of the tentacles. 
Solutions, how applied. Carbonate‘of Aitraue of P moines of 
Placed on the glands of the}| jl, of a sibs of a sey Of a 
disc, so as to act indirectly} grain, or grain, or grain, or 
on the outer tentacles .}} *0675 mg. *027 mg. *0169 mg. 
Applied for a few seconds)| ly, of a agin; of a Tete of a 
directly to the gland of an}| grain, or grain, or grain, or 
outer tentacle. . . .}/'00445mg.| ‘0025 mg. *000423 mg. 
Leaf immersed, with time]| sagygy of a potas Of a Tordsons Of a 
allowed for each gland to}| grain, or grain, or grain, or 
absorb all that it can. .}/+00024 mg.| *0000937 mg. | -00000328 mg. 
Amount absorbed by a gland 
which suffices to cause the]} 37455 of a 
aggregation of the proto-}| grain, or 
plasm in the adjoining||‘00048 mg. 
cells of the tentacles , 
From the experiments tried in these three different ways, 
we see that the carbonate, which contains 23-7 per cent. of 
nitrogen, is less efficient than the nitrate, which contains 35 
per cent. The phosphate contains less nitrogen than either 
of these salts, namely, only 21-2 per cent., and yet is far more 
efficient; its power, no doubt, depending quite as much on 
the phosphorus as on the nitrogen which it contains. We 
may infer that this is the case, from the energetic manner in 
