^8 On Camphor and tig Camphoric Acid, 



for obtaining the camphor of feveral volatile oils ; but he has neither defcribed Its chaw 

 rafter, nor fliewn in what refpeft it might differ from ordinary camphor. 



The experiments we are about to defcribe may perhaps hereafter afford fome light on 

 the nature of this fingular fubftance. 



We know that the earths, the faline earthy fubftances, and the alkalis, have no aflioii 

 upon camphor ; but as chemifts had hitherto employed the alkalis in combination with 

 carbonic acid, it was effentially neceffary to try the a£lion of the pure alkalis. 



1 {hall not here enlarge upon the various experiments I have made. It will be fufE- 

 cient to remark, that I have obtained no fatisfadtory refult. The camphor is always vola- 

 tilized. It feems as if a fmall quantity was diffolved ; but it is fenfible only to the fmell, 

 for I have not been able to afcertain its prefence by any other means. 



The acids diffolve camphor. The nitric acid is mofl: commonly employed for this pur- 

 pofe, to form a medical preparation known by the improper name of oil of camphor. 



I (hall not attempt to explain the inconveniencies and injudicious method of preparing 

 this oil. It is known that it is impoffibJe to ufe it in any vehicle whatever without rege- 

 nerating the camphor ; confequently there remained to medical praftitioners no other 

 means but of employing this oil alone, or the camphor united to alcoho!. But if we exa- 

 mine the aflion of this oil on the animal economy, it will be immediately feen that it can- 

 not be exhibited alone. 



Thefe confiderations engaged me in the fearch for the means of obtaining camphor in 

 the fluid ftate, without the addition of an acid. Though the refult of my experiments 

 has not been fuccefsful, it will neverthelefs be ufeful to fcience in fixing our notions re- 

 fpeding the nature of this fubftance. 



SECTION 11. 



Procejfesfor obtaining the Decompofiiicn of Camphor. 



TAKE 09C part of camphor and fix of clay. Let the. clay be pulverized In the dry ftate, 

 ijnd fifted through a fine fieve ; on the other hand, the camphor is to be pulverized by 

 means of alcohol, and the whole is then to be mixed together in a mortar. When the mix- 

 ture is well made, add a fmall quantity of water, not too much, but enough to admit of 

 forming the matter into a pafte, which is to be made into balls of the fize of an olive. 

 Place thefe on a hair fieve to dry in a ftove. 



When the balls are perfeftly dry, let them be Introduced into a retort, which is to be 

 placed Qti; » ,fand bath, with a receiver containing fome diftilled water, and well 

 luted at the neck. In this difpofition of the apparatus the retort muft be gradually heated, 

 and kept for feveral hours ip this ftate, after which the heat is to be raifed. 



If the heat be not well managed, it fometimes happens that part of the camphor fub- 

 limes to the rieck of the retort. This however is no reafonfor difcontinuing the procefs, 

 which muft be carried on fo long as any oil is feen to come over. The fire is then to be 

 put out } and when the appawtus is cold, the receiver may be unluted, and the fublinied 

 camphor, as well as the refidue'In the retort, muft hie taken out. The whole is' th^n 'to 

 be pounded In a mortar, and the operation recommenced as before, until, even by a con- 

 fidprable degree of heat, neither fublimation oor oil appears. 



AJecond 



