OVl THE SOUND FRODUefcD BY HIDROGEN GAS. 1*9 



* IS. A vefiel lined with lead, interfered by the veflel 12, 

 with whkfa it is foldered. 



14. A cock to draw off the fluid when prepared. 



15. A receiver of lead inverted in the tub. A hole, 16, 

 may be made in this receiver to let out the atmofpheric air 

 when it is plunged in the tub> which hole muft be ciofed be- 

 fore the difengagement of the gas begins. The inverted 

 receiver bears upon three projections of wood, which keep 

 it at a little diftance above the bottom of the tub. 



When the ftrength of the liquor obtained by this apparatus This laft appa.. 



was compared with ours, it was found that with equal pro- ^A^th S 



portions of materials and of water its difcolouring action upon the former. 



indigo was no more than about the half of ours. Confequently 



there is a real lofs in the confumption of thefe articles. This 



muft be attributed to the low degree of heat, which does not 



*jxpel the whole of the gas. I have neverthelefs judged that 



it would be of ufe to defcribe this ingenious mechanifm, the 



iimplicity of which will, no doubt, give fatisfaclion to artifts. 



It is obvioufly capable of improvement, either by placing on But It may be 



one iide a feparate furnace, with a land and ordinary diftilling lin P rove J b y 



y- i i i i , ^ , 1 i , raifin S the heat » 



veliel, whence the gas may be conducted beneath the re- and is very fim- 



ceiver by a leaden tube ; or, according to the actual dif- P le * 



poiition of the apparatus, a liquid or dry bath may be 



lubftituted to that of water, fo as to communicate a higher 



degree of heat, provided the temperature be le'fs than will 



melt lead, a condition which admits the defired extrication 



of the gas. 



IX. 



On the Sound produced by a Current of Hidrogen Gas puffing 

 through a Tube. * With a Letter from Dr. HiggIns, re- 

 flecting the Time of its Difcoveri/. 



1 NTO a glafs bottle is put fulphuric acid and iron filings, The flame of 

 through the cork of which a glafs tube is palled ; the upper ^o'Jfgh uttS 

 extremity is capillary : then by letting lire to the hidrogen iary aperture, 

 gas which efcapes by this extremity, a continued current or jet un cr a tu c * 



* Bulletin des Sciences, No. 56, An. 10; 

 Vol. I.— February. K of 





