Comparison of the Blowpipe of Hare and Brook. 89 



Although the experiments of Mr. Silliman date in 1812, 

 we have thought that they ought to be known upon our con- 

 tinent. They demonstrate, on the one hand, that Mr. Clark 

 has been anticipated in Ameiica, with respect to the fusion 

 of bodies in the flame of hydrogen and oxigen ; — and on the 

 other, that the blow-pipe of Hare gives results almost per- 

 fectly identical with those of Brook. 



Remarks by the Editor. 



Having, in company with Professor Griscom, used the 

 blowpipe of Brook, and repeated with it many of the 

 experiments cited above, we are constrained to agree 

 with Messrs. Gay Lussac and Arago, (an authority which 

 both on this point, and on that of priority, will proba- 

 bly be admitted as of the first import,J and to say 

 that we can perceive very little, if any superiority which 

 Brook's instrument has over the prior and original inven- 

 tion of Mr. Hare. The exact apportionment of the gases 

 is, at first view, a consideration of importance — but in prac- 

 tice, (and we speak from a long course of experience with 

 Mr. Hare's instrument,) it is really found of very small mo- 

 ment. A little habit in using the instrument, soon enables 

 the operator to decide by the eye, from the size and intensi- 

 ty of the flame — especially when directed upon any object, 

 whether the proportions are right, and nothing is easier than 

 to alter them, by simply turning the key of one stop cock, 

 or of the other, as may appear necessary. We can say with 

 the utmost confidence, that there is no difficulty on that 

 head, and the results with the two instruments sufficiently 

 establish this fact. 



Theory would probably lead us to expect much from the 

 effect of pressure — but here again we were, when using 

 Brook's instrument, greatly disappointed. We raised the 

 pressure, by forcing in the mixed gases till the flat sides of 

 the thick and strong copper parallelopiped, which is em- 

 ployed as a recipient, were swollen out till they were alj 

 distinctly convex, and yet the intensity of the flame did not 

 appear to surpass that produced by Mr. Hare's instrument, 

 used with the aid of a pressure of a few inches of water. 



Ought we, however, even from theory, to expect any 

 advantage from pressure, bevond that which mav cause the 



Vol. m No. 1. " 13. 



