SECT. II.] 



PROPERTIES OF STEAM. 



55 



The quantity of water of which the specific heat would be equivalent to the 

 heat absorbed by the vessels, Dr. Ure has not given ; but in assuming it to be 

 about 1660 grains, we shall be not far distant from the truth. Hence we have 

 32340 + 1660=34000 for the water equivalent to the specific heat of the cooling 

 apparatus ; and by the formula, (art. 75, note) 

 34000 x 6-5 



And 



200 



34000x3 

 200 



+49212 = 942, for water. 



+ -65 (175-45) = 425-5, for alcohol. 



The others being calculated in the same manner, afford the results in the last 

 column, taking the specific heat from the usual tables. Through an oversight in 

 calculation, Dr. Ure's numbers in the ' Philosophical Transactions ' are erroneous. 



82. A further correction might be applied for the quantity of steam remaining 

 in the retort, and the loss of heat in the operation. Dr. Ure has, in a recent cor- 

 rection for loss of heat, made the heat of conversion of water into steam 1000 ; and 

 under the impression that Count Rumford's are the most accurate experiments on 

 the subject, I am inclined to think this number about right. If for these sources 

 of loss we make a further allowance in Dr. Ure's experiments of the specific heat of 

 2000 grains of water, we shall have 



36000x6-5 



200 



+ 49-212 = 1007; 



and correcting the rest of the numbers in this manner, the following are obtained. 1 



Ure's Dictionary of Chemistry, art. Caloric. 



