Chap, i.] [ 379 



B.OOK VII. 

 O F W A r E R. 



CHAP. I. 



OFWATER IN GENERAL. 



Water a Ccmpotmd Body. Three States of Water. Water in a fluid 

 State. Florentine Experiment." fapour. Experiments afcertaining 

 tie Force of Vapour. Steam Engine. Ice. Phenomena of Freez- 

 ing. Of Tha<wing.-~Water expanded in the State of Ice. Immenfe 

 Force exerted by Water on p offing to that State. Why Ice is not 

 perfectly tranfparent. 



WATER was univerfally confidered as a fimple 

 elementary fubftance till the cfaemifts of the 

 prefent age proved, by experiments, the fubftance of 

 which has been ftated in a preceding volume *, that 

 it is in reality a compound body. Its principles have 

 been afcertained both by compofition and decompofi- 

 tion ; and one hundred parts of water are found to 

 confift of eighty-five parts of oxygen, and fifteen of 

 hydrogen, or the bafis of inflammable air. 



This very ufeful and necefiary fluid prefents itfelf 

 to our notice in three diftinc~b forms, namely, in its 

 liquid ftate, in the ftate of vapour or fteam, and laftly 



Book V. Chap. I. 



in 



