484 COMPOUND PRODUCTS. CHAP. I. 



warrant the conclusion that the ultimate ingredients 

 of camphor are carbon and hydrogene.* 



Though camphor is obtained chiefly from the 

 Laurus camphorata, yet it is known to exist in a 

 great many other plants, particularly labiate plants, 

 and has been extracted from the roots of Zedoary, 

 Sassafras, Thyme, Rosemary, Lavender. 

 Uses. ^ i s in uch employed in pharmacy and medicine. 



It is regarded as a powerful stimulant, and is found 

 to be peculiarly efficacious in urinary disorders. It 

 has been regarded also as a preventive against 

 contagion, if worn about the body and occasionally 

 applied to the organ of smell ; but its efficacy in this 

 respect seems doubtful. It is peculiarly offensive to 

 insects, and is consequently of great utility to pre- 

 vent their depredations in cabinets of natural 

 history. It is used also in the composition of 

 matches and other inflammable materials, parti- 

 cularly if they are to be exposed to the action of 

 water. 



SECTION XIX. 



Caoutchouc. 



How ob- THE substance denominated Caoutchouc was first 



tamed. introduced into Europe about the beginning of the 



last century. But from a use to which it is very 



generally applied of rubbing out the marks made 



upon paper by a black-lead pencil, it is better known 



* Thomson's Chemistry, vol. iv. p. 330. 



