15' On Camphor and its Acid, 



mull be throwrt on the cryftals in order to clear them of the portion of nitric acid which 

 may adhere to their furface. The moll certain indication that the cafnphor is acidified, 

 confifts in its cryftallization by the cooiijig of the fluid which remains in the retort. 



Purtfcaiion cf the Camphoric Acid. 

 This acid is purified by folution in hot diflilled water, filtration and evaporation of 

 rjearly half the fluid, or till the period at which a flight pellicle is formed. The cryftals of 

 camphoric acid feparate by cooling. 



ji Second Prvcefs. 



Another method of procuring the camphoric acid confifts in the ufe of nitric acid at 

 50 degree?, or fpecific gravity 1,532. This procefs is much fpcedicr than the former, but 

 its inconveniences arc fuch as do not entitle it to be preferred to the other. In fai5t, the 

 camphor is more fpeedily attacked by the concentrated acid ; but inftead of fubliming, it 

 pafles over into the receiver, and a portion is likewife carried off" in the gas which efcapes. 

 'I'hefe circum'ftances occafion a real lols in the product, as may be feen by the following 

 tables of the refults : 



By the firft method. " grammes. 



Nitric acid, at 36 degrees, 41b. 14 oz. or - - 2114,538 



Camphor, 40Z. or - _ _ - - 122,284 



Acid obtained, i4gros, or - - - - 53)498 



By the fccond method. 



Nitric acid, at 50 degrees, zlb. 12 oz. 2 gros, or - - 1352,168 



Camphor, 40Z. or - - - - - 122,284 



Acid obtained, 9 gros, or - - - - 34>392 



SECT. vir. 



Campljor and Oxygenous Gas. 



BEING defirous of knowing how camphor would be afFefled with oxygenous gas, I 

 made the following experiment: 



Oxygen gas" was obtained from the fuperoxygenated muriate of pot-a(h. After an in- 

 verted glafs vefTel was thus filled, it was transferred to the trough containing mercury, and 

 a fmall portion of water was pafl'ed to the furface of the metallic fluid. 



On the other hand, a fmall piece of camphor with a particle of phofphorus was placed 

 in a fmall cupel. A tube was then bended in fuch a manner and applied, that one of its 

 extremities was placed beneath the glafs jar, and the other in a pneumato-chemical trough, 

 beneath a jar filled with water. 



In this difpofition of the apparatus the phofphorus was fet on fire by means of a red-hot 

 iron. The inflammation was communicated to the camphor. Much caloric was difengaged 

 with a very brilliant flame ; the inner furface of the veflTel became covered with a black mat- 

 ter, which was detached by degrees, and floated upon the water over the mercury. A gas 

 was collefled at the fame time, which exhibited all the charaders of carbonic acid gas. 



This experiment therefore confirms the refult in Sedlion II. for it cannot be doubted but 

 tliat the matter in the retort was a true carbon. 



The 



