2 DESCRIPTION OF A BLOW-PIP&. 



jr any the travelling rhineralogift, and in every cafe they require 

 fome preparation. And even the ingenious contrivance of 

 Mr. Haas, though it permits the free ufe of the operator's 

 hands, is expenfive, and ftill requires the blowing through the 

 mouth. 

 Very Hfcful lamp When Profeflbr Pi&ct of Geneva vifitec! London laft year, 

 ProreiTor Pi&et. ^ e brought along with him and exhibited to his friends an appa- 

 ratus, which at the fame time that it is fimple and very port- 

 able, is the moft advantageous fubftitute for the blow-pipe, and 

 removes all its inconveniences. An imitation of this apparatus 

 was exhibited in the leclure-room of the Royal Inftitution, AI- 

 bemarle-ftreet. 

 Drfcriptlon of The drawing of this inftrument which I fubjoin, was copied 

 blowing die* ^ rom ^ at comm unicated by a friend. A, plate 1, is a tin-box 

 flame of oil by filled with common oil, ferving to feed the flame at F, thence 

 to be directed on the fubftance under examination, and at the 

 other flame, to heat the fpirit of wine contained in the copper or 

 tin lamp B. The boiling fpirit being converted into fteam by 

 the heat, ru flies through the bended tube C upon the flame of 

 the wick at F. Laftly, D is a Aider with loops and fcrews to 

 raife or lower the fpirit lamp. The whole being very fimple 

 and clear, any farther explanation would be needlefs. 

 Long ago ufed I do not know whether Profeflbr Picket pretends to be the 

 inventor of this apparatus; but certain it is, that Abbe Nollet 

 more than fifty years ago employed fuch a contrivance, as may 

 be feen in his VArt defaire Experiences. Another application 

 of the fpirit lamp for this purpofe I have read in the Annales de 

 Chimie, but do not recoiled in which volume. 



There is no doubt but the communication of the lamp above 

 defcribed will be acceptable to many of the readers of your ex- 

 cellent Journal ; whence, if you agree with me in this opinion 

 be fo kind as to infert it. 



I am, Sir, 



Your humble fervant, 

 N. N. 



ANNOTATION. W. N. 



Powerful effeft The application of the elaftic and combuftible vapour of al- 



of a fmalleoli- cohol to this ufeful purpofe is fo obvious, that it can fcarcely be 



'* appropriated as an invention. The glafs^blowers have long 



fold a littleimplement, confiding of an egg-fhaped ball, having 



aftern 



