FREEZING OF .ALCOHOL. 



16? 



that by a farther abstraction of caloric all liquids in their turn, 

 may be reduced to the solid state. If this be true, and we 

 were in possession of a method of sufficiently abstracting caloric, 

 all bodies whatever might be reduced to the solid state. We 

 should thus become acquainted with a great number of sub- 

 stances that we have hitherto had no opportunity of examining ; 

 many powerful agents would likely be obtained; many new" 

 and interesting compounds formed, and much light could not 

 fail to be thrown on the constitution of known substances. 



Directing my attention to this subject, in the summer of Mention and 

 1810, a method occurred to me, by which I imagined a greater dat ® ° f a me " 

 degree of cold might be produced than had hitherto been ob- ducingex- 

 tained. Although the power of this method appeared in treme cold, 

 theory almost indefinite, yet it was easy to foresee that in 

 practice many circumstances might at first concur to set limits 

 to its application ; from the nature of these circumstances, 

 however, it was to be expected, that some of them might be 

 considerably modified, and many of them might in time be 

 altogether removed ; and thus the practice made, in some de- 

 gree, to approximate to the theory. 



At the time this method occurred to me, the pressure of my 

 professional avocations did not allow me to prosecute it ; but, 

 as I anticipated some leisure in the following autumn, I imme- 

 diately began td provide, at any leisure moments I had, such 

 apparatus as I considered absolutely necessary, or was most 

 likely to be useful. The little dependence, however, which is 

 to be placed on general reasoning on such subjects, and the 

 apprehension that the method might have been previously 

 tried, and found insufficient by others, prevented me from pro- 

 viding any very extensive apparatus. 



My first experiment was tried in the following autumn. A therciome- 



The thermometer was filled and sealed by myself. The tube ' cr of a J co ^ o! 



isp, st, 798) 

 was previously tried by the common method, and found, as 



nearly as such tubes are commonly to be met with, of equal 



calibre throughout. The spirit with which it was filled was 



prepared by Richter's process, and afterwards re-distilled by 



itself. Its specific gravity at 62° was 798. The points 60° and 



100° were determined by a mercurial thermometer, which 



had been made with the usual precautions j the interval was 



divided into four spaces, each of which, of course, correspond 



to 



