SECT. II.] 



PROPERTIES OF STEAM. 



7-3 



Bettancourt's boiling point is not stated, but appears to have been at 173, l and 

 his results like Dr. Robison's are too small at low temperatures. 



Dr. Ure's experiments are confirmed by those of Mr. Dalton, and may be relied 

 on as approaching very near the truth. The formula, it will be observed, repre- 

 sents them with considerable accuracy. 



OF THE ELASTIC FORCE OF THE VAPOUR OF SULPHURIC ETHER. 



106. M. Cagniard de la Tour made several experiments on ether in the 

 same manner as those on alcohol, art. 104. The ether was converted into vapour 

 in a space less than twice its original volume by a temperature of 392. This 

 experiment was thrice repeated, with the same result, and 528 parts of air were 

 compressed to 14, giving an elastic force of 37'7 atmospheres. 2 



107. Other trials were made, the results of which are shown in the following 

 table. 



M. CAGNIARD DE LA TOUR'S EXPERIMENTS ON ETHER. 



1 Prony's Architecture Hydraulique, vol. ii. p. 180. 



3 The experiments on sulphuric ether may be very nearly represented by the formula, 



or 



- 2-25212) 



when the ether boils at 104 or 105 ; but for ether boiling at 98, the constant logarithm should 

 be 2-23953. 



In the above experiment the formula for ether boiling at 105 gives 48 atmospheres for its elastic 

 force at 392 ; but the correspondence with the tabular experiments is nearer. 



