On the Contraction of IVater it/ Ih-at. lip 



as a point of much curiosity and interest, I have endeavoured 

 to investigate the subject bv experiments conducted in a to- 

 tally different manner, equally calculated to exhibit the sin- 

 gular truth, but free from the objections to which the others 

 are liable. In then;, it was my object to provide, that 

 neither the changes of the actual volume of the water, nor 

 the alterations in the dimensions of the instrument, should 

 have any influence whatever. 



I have already taken occasion to state, that the purpose 

 of this paper is to prove, by experiments on the principle 

 now mentioned, that in the constitution of water there 

 really exists the singularity often noticed. 



I shall first state the plan of the experiments, and then 

 detail the particulars of the most remarkable of them. 



When any body is dilated, whether by heat or cold, k 

 necessarily becomes less dense, or specifically ligliter; and 

 the opposite effects result from contraction. This is the 

 circumstance, as every one knows, which causes various 

 movements among the particles of fluids, when any ine- 

 quality of temperature prevails in the mass ; hence these 

 particles arc little acquainted with a state of rest- 



If a partial application or subtraction of heat produce ;iii 

 inequality of density in a mass of fluid, the lighter parts 

 rise to the surface, or the denser fall to the bottom. 



It readily occurred, that I might avail myself of these- 

 movements, and upon statical principles determine the 

 question in dispute. 



I had only to examine attentively water, as it was heated 

 or cooled in a jar, and to observe, by means of thermome- 

 ters, what situation the warmer, and what the cooler parts 

 of tliis fluid affected. 



If I should lind that ice-cold water, in acquiring tempe- 

 rature, showed, in its whole progress, the warmer parts near 

 the top, it would indicate that water follows tl)e usual lau , 

 and is expanded like other bodies by heat. 



Or if I should observe that warm water, in cooling to tiie 

 freezing point, had the coldest portion uniformly at the 

 bottom, the same conclusion woidd follow ; while a dif- 

 ferent inference, and the existence of the supposed anomaly, 

 would be deduciblc should the event prove diflercnt. The 

 only circumstance I can figure to myself as tending in any 

 measure to render this mode of examining the point doubt- 

 ful, is, that water near its eongealnig point may have no- 

 little change of density occasioned by a small variation of 

 temperature, that its particles may be prevented by their 

 mTtia, or by the tenacity of the circnra'huiit uja-^s. from 



aisuimui.'' 



