on some of the leading doctrines of caloric , &c. 383 
several degrees above its point of congelation ; a fact which 
does not hold with regard to any other homogeneous 
liquid. 
If the specific heat of water, then, diminish as its tempera- 
ture advances from the freezing to the boiling point, an 
interval of 10® near 32 0 , will contain more caloric than ten 
degrees near 122°, and still more than the same intervals near 
212 0 . On this principle we can readily account for the results 
obtained by Mr. Dalton, in mixing with water at different 
temperatures a known proportion of ice ; though it is remark- 
able that this able chemist did not see in them any thing 
inconsistent with his own opposite views upon specific heat. 
“ 176°. 5 expresses the number of degrees of temperature, 
“ such as are found between 200° and 212 0 of the old or com- 
“ mon scale, entering into ice of 32°, to convert it into water 
of 32° ; i5o°of the same scale suffice, he says, for the same 
effect, between 122 0 and 130° : and between 45°and 50°, 128° 
are “ adequate to the conversion of the same ice into water. 
“ These three resulting numbers (128, 150, J76.5) are nearly 
“ as 5, 6 , 7. Hence it follows, that as much heat is necessary 
“ to raise water f in the lower part of the old scale, as is 
“ required to raise it 7 0 in the higher, and 6° in the middle/’* 
Mr. Dalton, instead of adopting the obvious conclusion, 
that the capacity of water for heat is greater at lower than it 
is at higher temperatures, and that therefore a smaller 
number of degrees of the former should melt as much ice 
as a greater number of the latter, ascribes the deviation 
denoted by these numbers, or their differences, to the gross 
errors of our thermometric graduation ; which he considers 
* New System, vol. i. p, 53. 
