J9r. Harems Defiagrator and Calorimotor. 97 



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Letter 11. — From Dr. Hare, on the peculiar and com- 

 parative effects of the Calorimotor and Deflagrator. Also, 

 an account of an improved and enlarged Deflagrator, 

 ^nd of some new experiments performed hy means of this 

 instrument. 



Philadelphia, March 5, 1822. 



My Dear Sir, 



m 

 _ % 



' In reply to your enquiries on the suhject of the Calo- 

 rimotor, and the expediency of employing one during your 

 lectures, it may be proper to mention, that the phenome- 

 na produced by it are more agreeable to the eye ^nd 

 therefore more popular, than any which can be performed 

 without greater difficulty. By the time the Calorimotor is 

 completely immcrged in the acid solution, the wire in the 

 forceps is rendered white hot, and takes fire, emitting thq 

 most brilliant sparks* In the interim, an explosion usual- 

 ly gives notice of the extrication of hydrogen in a quanti- 

 I ty adequate to reach the burning wire. Immediately af- 



ter the explosion, the hydrogen is reproduced with less in- 

 termixture of air, and rekindles^ corruscnting from among 



the forty interstices, and passing from one side of the ma- 

 chine to the other in opposite directions, and at various 

 times, so that the combinations are innumerable. The 

 flame assumes various hues, from the solution of more or 

 less of the metals, and a blazing froth, rolls over the sides 

 of the recipient. When the calorimotor is withdrawn from 

 the acid solution, the surface appears for many seconds 

 like a sheet of flaming foam. 



I refer you to the last paragraph of my memoir on th^ 

 Deflagrator, for some results obtained by calorimotors, of 



different sizes, which 1 deem to be scientifically impor- 

 tant.* 



The heat evolved by one galvanic pair has been found by the experi- 

 ments which I instituted, to increase in quantity, but todioiinish in intensi- 

 ty, aa the size of the surface naay be enlarged. A pair containing about fifty 

 «quare feet of each metal, will not fuse platina, nor deflagrate iron, however 

 small may be the wire employed ; for the heat produced in metallic wires is 

 not improved by a reductioa in their size beyond a certam point. Yet the 

 metals abovementioaed, are easily fused or deflagrated by small pairs, which 



Vol, V,~No, 1. 13 





