90 



Compound na- 

 ture of heat. 



Generation of 

 n.e. 



ON THE YOLK OF WOOI,. 



be feme reafon wliy (lie folid bafe h3drocren attaclies itfelf to 

 the caloric of (be one wire, and why (lie folid bafe oxygen is 

 always To ready to enter into combination with the caloric of 

 the other wire. 



Scheele has aflcrted the compound nature of the matter of 

 heat, and that all inflammable bodies contain a principle of 

 inflammability, which princijjle, by combining with his igne- 

 ous air, produces the phennmejiaof combuftion. It does not 

 appear that this opinion has been controverted by any dccifive 

 fa6l. We now know that fome principle belides caloric is 

 neceflary in the produfiron of one inflammable body, namely,. 

 of inflammable air; which principle, by combining with vital 

 or igneous air, produces combutiion. There-produced water 

 is common to both. 



I think upon a further profecution of this inquiry, it will 

 appear, that fire is generated during combuflion, that it is fire 

 alone, (that is, the principle which caufes the fenfation of heat) 

 that caufes all the phenomena of combuftion, and that it is, as 

 Scheele obferves, the water of his igneous air which forms the 

 additional weight of bodies after they are burned. I know of 

 no chemical faft that contradi6ls this explanation, in which no 

 new fubftance that is not fenfibly difcovered is introduced. 



A CORRESPONDENT. 



Experiments on the Yolk of Wool,folloived by fme Confiderations 

 on the Cleanfing and Bleaching of Wool. Bjj Cit. VAvauE- 



LIN.* 



Yolk of wool. >3EVERAL philofophers have thought that the yolk of wool 

 was a fatty matter; others from its diflblving in water could not 

 adoptthe fameopinion. Chemical analyfis alone could decide 

 this queftion, and this is what I propofed to myfelf in the work, 

 the refult of which I now offer. 



Aftion of water Ifl. Water deprives wool of much of its colour, and the 



upon woo. liquid acquires colour, odour and tafle. 



2d. The vvafliings of the wool is milky like an emulfion of 

 gum-refin, and palTes through paper with difficulty. 



* From theAnn.de Chimie, Fruclidor, An. XI. No. 141. 



3d. In 



