On Camphor and Us Acid, 157 



ftand alkaline proofs. The oxide of tin is ufeful in thefe procelTes, becaufe it is not eafily 

 attacked by acids ; but our oxide is abfolutely info'.uble. 



1 (hall conclude by a refle£lion which may render thefe refearches more interefting. 

 Wolfram, from which this oxide is obtained, is found in the territory of the (French) Re- 

 public. . Several mines are already known, and the French chemifts have been for fome 

 years paft employed in fimplifying the procefles by which it is feparated from foreign fub- 

 flances* . 



We may therefore hope that the properties I have here defcribed will fupply artifl* with 

 additional means of giving durability to the produftions of genius, and may open a new 

 branch of national induflry. 



IV. 



MJiraB of a Memnr on Camphor and the Camphoric Acid., read to the Flrjl Clafs of the 

 National Irjlitute of France, By Bouillon LA GjiANGE. 



[Concluded from Page tor, Vol. II.} 



___, Habitudes of Nitric Acid with Camphor. 



JL HE nitric acid has likewife a difFerentadion upon camphor frbnv that which we have 

 already mentioned. 



The Camphoric Acid. 



Kofegarten has informed us, that by diftilling nitric acid'eight times in fuccefllon from 

 camphor, an acid is obtained which differs in its properties from the oxalic acid. 



As thefe refults have not been confirmed by experiment, and 'it has not been demonflrated 

 that this acid is peculiar in its nature: and its affinity, I have repeated the experiments of 

 Kofegarten, of which we poflefs only a fimple notice in a letter tranflated from Crell's 

 Journal, and printed in the 27th volume of the Journal de Phyfique, page 298. The me- 

 thod of preparing this acid is as follows : 



Firfi P rocefi for preparing the Camphoric Aid.-. 

 Take fourouncesj or 122,284 grammes of camphor, which introduce-into a glafs retorf^ 

 and pour one poundj or 489,136 grammes of nitric acid, at 36 degrees, or fpecific gravity 

 1,33, and a\lapt a receiver well luted. Place the retort on a fand bath, and apply a gradual 

 hfeat. Much nitrous. and carbonic acid gas are difengaged j part of the camphor rifeSj 

 while another part feiaes the oxigen of the nitric acid. , When the .vapours ceafe to rife, un- 

 lute the veffcls ; return the fublimed camphor into the retort, .pour thereon another pound 

 , of the acid, and diftilla fecond time. This operation muft be repeated until the camphor is 

 totally acidified. Four pounds- and fourteen ounces of this nitrio acid are fufficient to aci*^ 

 dify four ounces of camphor. 



When all the camphor is acidified it cryftallizes in the remaining fluid. . Tlie whole 

 muft then be poured on a filter after previous decantation of the acid, and diftilled water 



• Journal desMine5,.No, XIX.. G. Our Cornifh, mines alfo^alTQid the ores of .tungftfn..N.-, 



