Memoir on Sulphuric Ether. ATA 
ter are too large, so that the mean of the 
two series is a near approximation to the 
truth. 
Experiments on the force of aqueous steam 
in high temperatures, have been lately made 
by Mr. Southern of the Soho, Birmingham,* 
and by Dr. Ure of Glasgow,t the results of 
which agree very well with each other, and 
- with the mean of my two theoretic tables. 
As for the force of steam below 212°, no one 
has found any material variation from those 
in my first table; indeed scarcely any one 
seems to have attended much to those below 
. * Dr. Robison’s Works by Dr. Brewster. 
_ + It would have given me great pleasure to have been 
able to adduce Dr. Ure’s experiments on ether also, in cor- 
roboration of my early experiments, and of the general 
principles thence derived; a stronger condemnation of those 
principles could not have been brought forward, than their 
agreement with the results of Dr. Ure on ether vapour.—A]j 
the information we have given as to the quality, &c. of 
his ether, is contained in the following paragraph, “ The 
ether of the shops, as’ prepared by the eminent Londou 
Apothecaries, boils generally at 112° ; bat when washed 
with water or redistilled, it boils at 104° or 105°. It may, by 
rectification, however, be made to boil at a still lower tem- 
perature”.—We are presented. with two series of experi- 
ments on the force of ether vapour; the first begins at 34° 
with the foree 6.2, and ends at 104°, with the force of 30 
inches of mercury; the second. begins at 105° with the 
same force, and ends: at) 210% with the force 166 inches. 
