the specific heats of certain solids. 275 



in repetition. Before closing these observations it may be proper to 

 add, that when in any given experiment the thermometer which 

 measures the temperature of the water is witlidrawn to insert the 

 hot body and afterwards returned to the hquor, it will, under certain 

 circumstances of the air, be found to have changed its indication, 

 the moisture remaining upon its surface causing it to take the " evap- 

 orating point" as its stationary position. In this case it must be no- 

 ted on again immersing the bulb, and the change it has undergone 

 recorded and subsequently multiplied by the equivalent of the im- 

 mersed part of the thermometer to obtain the requisite correction. 



The table exhibiting the data, calculations and results of experi- 

 ments to determine specific heats in the manner above described, 

 will contain the following particulars. 1st. The number of the ex- 

 periment ; 2d. The kind of heating liquid employed ; 3d. The dew 

 point of the apartment ; 4th. Its evaporating point ; 5th. The 

 weight of solid under trial ; 6th. The temperature at which it is im- 

 mersed ; 7th. Temperature of the water ; 8th. Temperature of the 

 thermometer when immersed ; 9th. Temperature of the air ; 10th. 

 Resulting temperature of the water ; 11th. Gain of temperature by 

 the water containing vessel and thermometer ; 12th. Loss of tem- 

 perature in the solid ; 13th. Time occupied by the experiment; 

 14th. Weight of water in grains ; 15th. Equivalent of the contain- 

 ing vessel in grains of water ; 16th. Equivalent of the part of ther- 

 mometer immersed ; 17th. Sum of the equivalents in water, con- 

 taining vessel and thermometer; 18th. Product of the preceding 

 column by the gain of temperature; 19th. Product of the weight 

 of solid by its loss of temperature ; 20th. Correction obtained by- 

 multiplying the equivalent of the thermometer by its variation from 

 the initial temperature of the water. (This correction will be either 

 positive or negative, according as the evaporating point is below or 

 above the initial temperature.) 21st. Specific heat obtained by di- 

 viding the 17th column, corrected, by the 18th. Other corrections 

 may be inserted when necessary according to the observations already 

 made. To present the several cases to which we have referred in 

 the preceding remarks, the following formulas may be adopted. 



1. When the specific heat of the containing vessel is to be ascer- 

 tained by first filling it with water of a known temperature and letting 

 it stand until we are sure that a stationary point has been attained, 

 then emptying it and instantly refilling with water of a different tem- 



