Chap. IX. CAMPHOR. 209 



able time in a very strong solution. On the whole, it seems 

 that the poison of the cobra acts far more injuriously on the 

 protoplasm of the higher animals than on that of Drosera. 



There is one other point which may be noticed. I have occa- 

 sionally observed that the drops of secretion round the glands 

 were rendered somewhat turbid by certain solutions, and more 

 especially by some acids, a film being formed on the surfaces of 

 the drops; but I never saw this effect produced in so con- 

 spicuous a manner as by the cobra poi^son. When the stronger 

 solution was employed, the drops appeared in 10 m. like little 

 white rounded clouds. After 48 hrs. the secretion was changed 

 into threads and sheets 'of a membranous substance, including 

 minute granules of various sizes. 



Camphor. — Some scraped camphor was left for a day in a bottle 

 with distilled water, and then filtered. A solution thus made is 

 said to contain yooo ^f its weight of camphor; it smelt and 

 tasted of this substance. Ten leaves were immersed in this 

 solution; after 15 m. five of them were well inflected, two 

 showing a first trace of movement in 11 m. and 12 m. ; the 

 sixth leaf did not begin to move until 15 m. had elapsed, but 

 was fairly well inflected in 17 m. and quite closed in 24 m. ; the 

 seventh began to move in 17 m., and was completely shut in 

 26 m. The eighth, ninth, and tenth leaves were old and of 

 a very dark red colour, and these were not inflected after an 

 immersion of 24 hrs.; so that in making experiments with 

 camphor it is necessary to avoid such leaves. Some of these 

 leaves, on being left in the solution for 4 hrs., became of a 

 rather dingy pink colour, and secreted much mucus ; although 

 their tentacles were closely inflected, the protoplasm within the 

 cells was not at all aggregated. On another occasion, however, 

 after a longer immersion of 24 hrs., there was well marked 

 aggregation. A solution made by adding two drops of campho- 

 rated spirits to an ounce of water did not act on one leaf; 

 whereas thirty minims added to an ounce of water acted on two 

 leaves immersed together. 



M. Vogel has shown* that the flowers of various plants do not 

 wither so soon when their stems are placed in a solution of cam- 

 phor as when in water; and that if already slightly withered, 

 they recover more quickly. The germination of certain seeds is 

 also accelerated by the solution. So that camphor acts as a 

 stimulant, and it is the only known stimulant for plants. I 



* ' Gardener's Chronicle,' 1874, p. G71. Nearly similar observations 

 were made in 1798 by B. S. Barton. 



