CHAP. VII. CARBONATE OF AMMONIA. 143 



analogous cases with air thoroughly permeated with 

 the vapours of chloroform and ether. 



Minute particles of the carbonate were added to the 

 secretion surrounding several glands. These instantly 

 became black and secreted copiously ; but, except in 

 two instances, when extremely minute particles were 

 given, there was no inflection. This result is analo- 

 gous to that which follows from the immersion of 

 leaves in a strong solution of one part of the carbonate 

 to 109, or 146, or even 218 of water, for the leaves 

 are then paralysed and no inflection ensues, though 

 the glands are blackened, and the protoplasm in the 

 cells of the tentacles undergoes strong aggregation. 



We \\ill now turn to the effects of solutions of the carbonate. 

 Half-minims of a solution of one part to 437 of water were placed 

 on the discs of twelve leaves ; so that each received -^ of a grain 

 or '0675 mg. Ten of these had their exterior tentacles well 

 inflected ; the blades of some being also much curved inwards. 

 In two cases several of the exterior tentacles were inflected in 

 35 m. ; but the movement was generally slower. These ten 

 leaves re-expanded in periods varying between 21 hrs. and 

 45 hrs., but in one case not until 67 hrs. had elapsed ; so that 

 they re-expanded much more quickly than leaves which have 

 caught insects. 



The same-sized drops of a solution of one part to 875 of water 

 were placed on the discs of eleven leaves; six remained quite 

 Unaffected, whilst five had from three to six or eight of their 

 exterior tentacles inflected ; but this degree of movement can 

 hardly be considered as trustworthy. Each of these leaves 

 received r ^ of a grain ('0337 mg.), distributed between the 

 glands of the disc, but this was too small an amount to produce 

 any decided effect on the exterior tentacles, the glands of which 

 had not themselves received any of the salt. 



Minute drops on the head of a small pin, of a solution of one 

 part of the carbonate to 218 of water, were next tried in the 

 manner above described. A drop of this kind equals on an 

 average -$ of a minim, and therefore contains T ^ of a grain 

 ('0135 mg.) of the carbonate. I touched with it the viscid 

 secretion round three glands, so that each gland received onlj 



