Description of M. Montgolfier's Calorimeter . 241 



goodness of die workmanship bv running over it several 

 times, it flew off again and returned with a new load, with 

 which it began to form a new cell. 



If the faculty of modifying the conduct of an individual 

 according to circumstances is one of the characteristics of 

 reason, the fact I have now mentioned is surely a proof of 

 reasoning in an insect. The wasp had remarked the unex- 

 pected derangement which had been made during its ab- 

 sence ; the clay which it brought was intended for a new 

 cellule ; but observing the mischief done to the old ones, it 

 repaired them before building any more. 



XXXVTI. Description and Manner ofusing'M. Montgol- 

 fier's Calorimeter, an Apparatus for determining the com- 

 parative Quantities of Heat furnished by various Descrip- 

 tions of Combustibles *. 



J- he proper application of combustibles is one of the most 

 important objects in all the processes of the arts, more paiv 

 ticularly in chemical operations ; it is equally useful to 

 ascertain- what advantage in point of qeconomy results from 

 the employment of this or that kind of fuel, and to deter^ 

 mine the force of the caloric disengaged from the sub- 

 stances which we burn. 



Equal quantities of different kinds of combustible? do 

 not always yield the same degree of heat; and it re- 

 quires a longer space of time to disengage a given quan- 

 tity of caloric from some combustibles than from others. 

 The success of an operation very often depends upon the 

 promptitude with which it is executed. Manufacturers, 

 distillers, and agriculturists ought consequently to attach a 

 great deal of importance to the knowledge of the most ceco- 

 nomical fuel, or what are the effects which result froin a 

 given quantity of any particular kind ; in short, it ought 

 to he distinctly ascertained what is the most certain and the 

 easiest method of determining the difference of the action of 

 caloric. 



• From Journal r/r.< Mines, vol. xviii. 



Vol. 25. No. 99. August 1806. Q M, Mont- 



