SULPHURIC ACID FOR WATER. 377 
I have one other experiment; but, as it was 
conducted in a manner similar to the preceding, 
it may be unnecessary to enter into detail re- 
specting it: it will, perhaps, be enough, if I give 
its result in the following table, together with 
the results of those which I have more fully en- 
larged upon. 
Temperature at Evaporating 
Degree of concentration effected- 
xperi-| which the con- fave by which | Pressure under which 
mat naw | Rogtagche | "eae" | nyo | ea Oe 
Inch of Sark’ an 
Mercury. Inches of Mercury. * 
Ist 57° 0.61 0.90 71.53 1.814 
3rd 48 0.46 0.90 70.69 1.8075 
8th 32 0.26 0.90 67.80 1.7762 
2nd 17 0.15 29.81 26.78 1.249 
4th 48 0.46 29.30 62.77 1.7071 
7th 36 0.30 28.34 to 28.97 58.10 1.6405 
9th 55 0.58 29.57 66.40 1.7600 
From Professor Graham’s statements in his 
* The specific gravities here given are from the results of 
experiments of my own, carefully conducted upon the acid 
whose degree of purity I have described in a note, page 355, 
in this paper. And, except in the instance of sp. gr. 1.249, 
a very remarkable coincidence may be observed to exist, 
between them and the per centages of anhydrous acid, with 
those given by Dr. Dalton (New System of Chemical Philo- 
sophy, vol. 1, part 2, page 404). The per centages given by 
Dr. Ure in his table (Chemical Dictionary) in the same in- 
stances appear to be between 2 and 3 too high. The per 
centage given by Dr. Dalton, in the instance of sp. gr. 1.249, 
appears to be about 1.8 too low; and that by Dr. Ure, nearly 
1 too high. 
' 3B 
