70 THEORY OF CHEMISTRY. 



ccived a letter from a friend in Paris, in which I find that 



great account is made of the observations of Mr. Cruickfhank, 



fo that it is now taken for granted that I mtifl accede to the 



new theory, I beg you would add to my former letter, that 



ftanlflbindons Mr ' Cruickmank himfelf abandons the- molt fundamental prin- 



water ?s the fole ciple of that theory, which is, that the only fource of inflam- 



fource of in- mable air of any kind is water ; and he makes it not neCeflary 



flammable air. r . . .. ^ _ _ _ ,_ . #.,..* ,, 



which Lavoifier purpote. Mr. Lavoifier, treating of the inflammable 



thought eflential a » r from charcoal and water, which is limilar to that from 



to his theory, charcoal and finery cinder, fays, (Elements of Qhjmifiry, p. 87 



of the Englijk tranjlation) " It cannot poffibly be dif engaged 



from the charcoal, and mult confequently be produced from 



the water." According to the new theory, the union of 



oxigen, which is fuppofed to come from the finery cinder, with 



carbon from the charcoal, mull form fixed air, and not any 



Inference. kind that is inflammable. Mr. Cruick(hank therefore mull: 



abandon the new theory, in order to maintain his peculiar 



hypothefis. 



If I do not receive a better defence of this new theory from 

 its able fupporters in France, I fliall conclude it to be inca- 

 pable of defence, and that, as becomes ingenuous men, they 

 will abandon it, as Mr. Cruiekfliank has virtually done. 



I am, dear Sir, 



Your's fincerely, 

 Northumberland, Feb. 20, 1802. J. PRIESTLEY. 



P. S. I have not any Number of your Journal of a later date 

 than that for April laft. 



IV. 



Experiments upon the tanning Principle, and Refections upon the 

 Art of Tanning. By Cit. Merat Guil lot, Apothecary 

 at Auxerre. 



prouft's procefs 1 HE tedioufpefs of the procefs indicated by Mr. Prouft for 

 tL tedious^ U ~ 0Dta ' n ' n g ^ ie tanin, induced me to make fome experiments, 

 and to endeavour to find a more fpeedy method of procuring 

 it : the following is the refult of my inquiries : 



1. I 



