472 Memoir on Sulphuric Ether. 
100°, which I was most anxious to have cor- 
rect.—The force of steam at 32° isan impor- 
tant element; [ have spent much time and 
labour upon it, both before and since my first 
table was published; it is not less, I think, 
than .2 of an inch, nor more than .3; these 
being the extremes of my experiments ;. 
perhaps .25 is very near the truth. 
My table of the force of alcoholic vapour 
represents it too high for temperatures below 
60°, and for those above rather too low. These 
errors arose partly from the alcohol not being 
free from water, and partly from a mistake, 
as I now apprehend, in fixing a standard 
mark on the alcohol barometer.—They are 
but small and of little importance, as the 
observations were not used in establishing 
general principles. An improved and more 
extended series of observations on the force 
of alcohol vapour has recently been published 
What the specific gravities of the two kinds of ether used 
were, and whether the ethers used were obtained from the 
very inferior ether of 112°, by washing, or by distillation, 
are important points, concerning which we are not informed, 
However, Dr, Ure contrives to blend these two disjointed 
series, and to compare the results with those of mine made 
upon ether which boiled at 98°; and finding great dis- 
crepances, he concludes my results on ether and principles 
deduced from them are pregnant with errors. 
