On Camphor and its Acid. irj 



The water which had been placed under the jar became very odorant, and its fmell was 

 abfolutely the fame as that of the oil obtained by the procelTes already defcribed. It was 

 acid, and reddened the tincture of turnfol. Lime water afcertained the prefence of carbonic 

 acid in this water ; but upon adding an excefs of the carbonic acid the precipitate was not 

 taken up j which fa6t led to a fufpicion that another acid was prefent, and in faft a calcare- 

 ous camphorate was obtained. 



1 obferved that it was nece/Tary to add a fmall portion of phofphorus to the camphor, 

 which otlierwife would not have taken fire. For an ignited body only diflipates it in vapour, 

 and it cannot be inflamed but by the contaft of a body at a much more luminous or higher 

 degree of heat. 



SECT. Vlll. 

 CharaElirs of the Camphoric Acid, 



THE camphoric acid has a flightly acid bitter tafte, and reddens the tin£lure of turnfol. 

 It is cryftallizable, and a mafs of its cryftals refembles the muriate of ammoniac. By ex- 

 pofure to the air it efBorefces. Cold water diflblves it with difficulty.. One ounce of water 

 at the temperature of lo or i2 degrees of Reaumur, takes up no- more than fix grains; 

 whereas at the boiling heat it dilTolves 48 grains. When this acid is placed on ignited coals 

 it emits a denfe aromatic fume, and is entirely difllpatcd. By a gentler heat it melts and, 

 is fublimed. 



If the camphoric acid be put into a porcelain tube (heated), and oxygen gas be pafl'ed 

 through, the acid does not undergo any change, but is fublimed. 



By mere diftillation our acid firft flows and- then fublimes; bywhich procefs its- proper- 

 ties are in fome refpe<fl changed. It no longer reddens the tincture of turnfol, but acquires 

 a briflc aromatic fmell ; its tafte becomes lefs. penetrating, and it is no longer, foluble either 

 in water or the fulphuric and muriatic acids. Heated nitric acid turns it yellow and dif- 

 folves it. Alcohol likewife diflblves it ; and i£ this folution be left in conta(5l with the air 

 of the atmofphere it cryftallizes.. 



Camphoric acid does not produce any change in fulphur ; alcohol and the mineral acids 

 totally diflTolve it ; and fo likewife do the volatile and the fat oils. It forms combinations 

 with earths, alkalis,, and metallic fubftances.. We fhall give a. more particular account of 

 thefe faline combinations in another Memoir. 



Among metallic folutions^it decompofes only the fulphate and the muriate of Iron. 



It produces no change in the folution of indigo by fulphuric acid, nor id the tin£lure of- 

 nutgalls. It has no aiTrion. on lime-water.. 



Concliifion. — From all thefe fafls it follows, that camphor is a vohtile oil rendered con- 

 crete by carbon ; that thefe two diftindt pr«du£ts may be obt-iined by the n»edium of alu- 

 irine; and laftly, that by treating camphor with the nitric acid, another peculiar acid is 

 obtained which differs from all the known vegetable acidf, 



I. By its cryftallization. 2. Its fparing folubility in cold water. 3. Its burning with- 

 out leaving any refidue,- 4. Its not precipitating lime-water. 5., Its producing no change 

 in the fulphuric folution of indigo — a difference which remarkably diflinguifhes it from the 

 fuberic acid which turns the fame folution green; and 6. By the formation of peculiar falts, 

 every one of which exhibit a blue flanie with the blow-pipe.. 



