tfie Weight ascribed to Heat. 5 



manner in which the water lost the additional weight 

 which it had appeared to acquire upon being frozen 

 when it was afterwards thawed, as also a sensible differ- 

 ence in the quantities of weight apparently acquired in 

 the different experiments, led me to suspect that the 

 experiment could not be depended on for deciding the 

 fact in question. I therefore set about to repeat it, 

 with some variations and improvements ; but before I 

 give an account of my further investigations relative to 

 this subject, it may not be amiss to mention the method 

 I pursued for discovering whether the appearances men- 

 tioned in the foregoing experiments might not arise 

 from the imperfections of my balance ; and it may like- 

 wise be proper to give an account, in this place, of an 

 intermediate experiment which I made, with a view to 

 discover, by a shorter route, and in a manner less ex- 

 ceptionable than that above mentioned, whether bodies 

 actually lose or acquire any weight upon acquiring an 

 additional quantity of latent heat. 



My suspicions respecting the accuracy of the balance 

 arose from a knowledge which I acquired from the 

 maker of it of the manner in which it was con- 

 structed. 



The three principal points of the balance having been 

 determined, as nearly as possible, by measurement, the 

 axes of motion were firmly fixed in their places, in a 

 right line, and, the beam being afterwards finished, and 

 its two arms brought to be in equilibrio, the balance 

 was proved, by suspending weights, which before were 

 known to be exactly equal, to the ends of its arms. 



If with these weights the balance remained in equi- 

 librio, it was considered as a proof that the beam was 

 just ; but if one arm was found to preponderate, the 



