440 On the Comhivation of Acids 



noticed in those Memoirs ; one only has been subjected to 

 a new examination, and that is the oily matter. 



When carefully purified by water and potish, it has the 

 following properties, some of which have, been already ob- 

 served in the memoirs I shall quote. It does not redden 

 turnsole paper ; it is white; it has a cool taste siinilar to 

 that of mint, and a particular but not ethereatcd smell •, it 

 is heavier, yet less volatile, than water ; it is very soluble in 

 alcohol, but very slightly in water. ^ It is volatilized by 

 distillation with nitric acid, and partly decomposed ; but the 

 products of this decomposition vary according to the 

 strength of the acid used. If the nitric acid he weak, much 

 muriatic acid is produced, and liitle oxy-muriatic : if, on 

 the contrary, the acid be concentrated, little muriatic acid 

 is procured, but much oxy-muriatic acid : of course this 

 substance contains a very considerable quantity of muriatic 

 acid. In the same n)anner, when it is passed through a 

 red-hot iron tube a large quantity of acid is disengaged. 

 Yet it is decomposed but very slowly by the strongest al- 

 kalis, even when dissr.K'ed with them in alcohol: hence 

 the couclusion must be drawn, that the muriatic acid it 

 contains is intimately comliined with another substance. I 

 have not vet succeeded in discovering what this substance 

 is, because I iiave not been able to separate it from every 

 thing else. Whatever that may te, it is certain that it is 

 capable like the alkahs of neutralizing acids ; and it may 

 be presumed that it contains a large quantity of carbon, 

 since in the decomposition of alcohol and oxy-niuriatic 

 acid, much water and very little carbonic acid are pro- 

 duced. 



But of all the vegetable substances, I am acquainted with 

 none that possess the property of uniting themselves to 

 acids, in a more eminent degree than some of the essential 

 oils; perhaps even all of them enjoy this properly. That 

 of turpentine absorbs nearly one-third its weight of muri- 

 atic acid gas, and becomes converted, with the emission of 

 much heat, into an almost entire crystalline substance. 

 Kind some years since discovered it; its nature was after- 

 wards studied bv Tromsdorff and some French philoso- 

 phers, and lest of all by Gehlen. All ilicse chemists ex- 

 cept Gchlen have considered it as an artificial camphor, 

 because it had the smell, volatility, lustre, whiteness, and 

 many other properties of natural camphor; and comparing 

 the action of muriatic acid on oil of turpentine, with that 

 of sulphuric acid on vegetable substances, they have con- 

 ceived that the transformation of this oil into camphor is 



solely 



