£02 DESCRIPTION OF A NEW CALORIMETER. 



if we add water at 100°, represented by space 4, to water at 

 50°, represented by space Sj ; J5 degrees taken from space 4 

 of large capacity, not only go to fill up space 3, represent- 

 ing 75 9 > but also to till up space 1, the increased capacity 

 gained by 50° in rising from the freezing point. 



Although geometrical figures are no evidence of the truth 

 of a chemical doctrine, and should be avoided unless tending 

 tp illustrate the subject, yet I thought it necessary to call 

 them to my aid, the uore especially as Dr. Crawford has 

 dwelt on them at xnt length*. 



Other fluids From these jenments we may analogically infer, that 



obey a similar . ., , , , n ■ , . , 



l aw# similar laws regulate other fluids in a greater or less degree; 



and that neither the mercurial, nor any other thermo- 

 meter, is a faithful index of the quantity of caloric. Thus 

 if the capacity of water increase, it does not bespeak the 

 quantity of caloric thrown in at different temperatures. But, 

 as this is a most important investigation, I will defer the dis- 

 cussion of it to a more voluminous detail; for, should my 

 experiments undergo the ordeal of critical investigation, and 

 be established as facts, the thermometer must be regulated 

 according to the increasing- capacity of the fluid, before we 

 can determine the exact quantity of caloric communicated, 

 and there must also be some other method adopted for prov- 

 ing the regularity of mercurial expansion. 

 The apparatus I •HI conclude by remarking, that the apparatus abstract- 

 lost more calo- e fi more caloric in rising from 48° to 97°, than from 150° to 

 than at a high l66°, and therefore, in that respect, there can be no source 

 temperature. f fallacy. 



Sir, I beg leave to remain, 



Your very obedient servant, 



JOSEPH READE, M.D. 



Dimensions of P. S. The calorimeter I used held in the interior com- 



the calonme- p ar tment, No. 1, 6oz. of water, and in the second ]0| oz. 

 ter used. r . „ . . . x 



consequently, if equal quantities were used, the increase 



would be much more. 



VII. 



* The simple statement of the argument is, that, if the capacities an- 

 swering to any successive number of degrees of the thermometer be 

 supposed to increase by the augmentation or addition of any constant 



quantity, 



