SECT. XVIII. CAMPHOR. 447 



water, on the surface of which it swims, a singular 

 phenomenon ensues. The water surrounding the 

 fragments is immediately put into commotion, ad- 

 vancing and retiring in little waves and attacking 

 the fragments with violence. The minuter frag- 

 ments are driven backwards and forwards upon the 

 surface as if impelled by contrary winds. If a drop 

 of oil is let fallen on the surface of the water it pro- 

 duces an immediate calm. This phenomenon has 

 been attributed to electricity. Fourcroy thinks it is 

 merely the effect of the affinities of the camphor, 

 water, and air, entering into combination.* 



It is not altered by exposure to the air ; but it is Properties, 

 so volatile that it evaporates completely if exposed 

 to it in warm weather. It is insoluble in water, to 

 which however it communicates its peculiar odour. 

 It is soluble in alcohol from which it is again pre- 

 cipitated by water. 



It is soluble in acids, and its solution in nitric 

 acid, which is yellow, is known by the name of oil 

 of camphor. 



It melts at the temperature of 300 ;-}- and is so 

 inflammable that it will burn even on the surface of 

 the water. It burns with a bright flame and leaves 

 no residuum. If formed into a paste with water 

 and alumina, and distilled in a glass retort, the pro- 

 ducts are volatile oil, camphoric acid, carbonic acid 

 gas, and carburetted hydrogene gas, with a residuum 

 of charcoal and alumina, in such proportion as to 



* Connaiss. Chim. voJ.viii. p. 9- t Ibid. vol. viii. p. 10. 



