8 An Inquiry concerning 



Having thus removed my doubts respecting the ac- 

 curacy of my balance, I now resumed my investigations 

 relative to the augmentation of weight which fluids have 

 been said to acquire upon being congealed. 



In the experiments which I had made, I had, as I 

 then imagined, guarded as much as possible against 

 every source of error and deception. The bottles being 

 of the same size, neither any occasional alteration in the 

 pressure of the atmosphere during the experiment, nor 

 the necessary and unavoidable difference in the densities 

 of the air in the hot and in the cold rooms in which 

 they were weighed, could affect their apparent weights ; 

 and their shapes and their quantities of surface being 

 the same, and as they remained for such a considerable 

 length of time in the heat and cold to which they were 

 exposed, I flattered myself .that the quantities of mois- 

 ture remaining attached to their surfaces could not be 

 so different as sensibly to affect the results of the experi- 

 ments. But, in regard to this last circumstance, I after- 

 wards found reason to conclude that my opinion was 

 erroneous. 



Admitting the fact stated by Dr. Fordyce, and 

 which my experiments had hitherto rather tended to 

 corroborate than to contradict, I could not conceive 

 any other cause for the augmentation of the apparent 

 weight of water upon its being frozen than the loss of 

 so great a proportion of its latent heat as that fluid is 

 known to evolve when it congeals ; and I concluded 

 that, if the loss of latent heat added to the weight of 

 one body, it must of necessity produce the same effect 

 on another, and consequently, that the augmentation of 

 the quantity of latent heat must in all bodies and in 

 all cases diminish their apparent weights. 



