377 



DENSITY OF WATER. 



it to be 112", upon the authority of my paper.* Yet in his 

 anfwer to the Edinburgh reviewers, he has mentioned tiiis 

 eftimate of the melting point of fperraaceti as one of his ac- 

 knowledged errors, and upon the authority of Dr. Gibbes, 

 fixes it at 1 1 j^. This circumftance determined me to repeat 

 the experiment ; I employed a very delicate thermometer, and 

 ufed every requifite precaution ; the refult was that the inflru- 

 ment defcended to a little above the \ \'2th degree, and remained 

 ftationary until the fubftance was become folid. I may add 

 that Dr. Irvine, in fome experiments related in the ninth vol. 

 of your Journal, fixes the point at 113°, which agrees fo 

 nearly with my obfervations, as to afford rae an additional con- 

 fidence in their accuracy. 



I am, Sir, 



Your obedient fervant, 



JOHN BOSTOCK. 



Liverpool, April 9, 1 806. 



ir. 



Jnvefiigation of the Temperature at ivkich Water is of greateji 

 Den/ity, from the Experiments of Dr. Hope on the Contra^lion 

 of Water by Heat at low Temperatures. In a Letter from Mr. 

 JoiiN Dalton. 



To Mr. NICHOLSON. 

 ' SIR, 



1.N your Journal for February 1805 was inferted a letter of Reference tfl a 



mine containing certain facts relative lo the fubje6t of "^J P'C" s^cTtionTn'"^" 



fent communication, which led me to diibelieve the common which the max- 



opinion that water is denfeft at 40^, and inclined me to think ''"""' denfity o 

 , "^ , ' . watrr was taken 



it is at 32^. Since that time my attention has again been at 32°. 



turned to the fubjed; fome fmall but immaterial corredions 



of the fads have been made and additional ones obtained, by 



which I have been enabled to demonstrate, at leaft to my own 



fatisfadion, that the temperature at which water is of great- Prefent infer- 



efl dentity is at or near 36« of Fahrenheit. The refulls have ^"^/ ^^^ '^ '^ * 



lately been communicated to the Manchefter Society, and may 



* P.ige512, 



perhaps 



