Scientific Intelligence. — Mechanical Philusopluj. 179 



duce the heat as not to affect the organs. Many persons have per- 

 ished in conflagrations, altogether from having their organs of respi- 

 ration destroyed, as has been proved by the autopsy. It is possible 

 that those interior lesions may have been occasioned by heated aque- 

 ous vapor, v^hich retains its caloric better than air. 



The grand duke of Tuscany has had six of these dresses prepared 

 for the city of Florence. 



M. Aldini shewed before the Philosophical Society of Geneva, that 

 a loose tissue of asbestus intercepts the flame of a candle or spirit of 

 vs^ine lamp, as well as a metallic gauze of the same contexture. This 

 gives new force to the objections to Davy's theory of the eftect of 

 wire gauze, for in this case the metal, which is a substance of the 

 highest conducting power, is replaced by one which is a slow con- 

 ductor. — Bib. Univ. Aout, 1829. 



7. Plumbago instead of oil in watches and chronometers. — M. 

 Hebert appears to have well ascertained that plumbago, well pre- 

 pared by rubbing and repeated washings, to remove all the particles 

 of gravel which are more or less found in the best specimens, is 

 preferable to oil in watch movements. It is applied with a hair pen- 

 cil, either in powder or mixed with one or two drops of pure alcohol. 

 It adheres promptly to a pivot of steel, as well as to the surface of 

 the hole in which it turns, so that the rubbing surfaces, no longer 

 present a metal to a metal, but plumbago to plumbago ; they acquir- 

 ed a pohsh which yields only to that of the diamond ; the retardation 

 from friction and the wearing becomes almost nothing. An astro- 

 nomical clock made by M. Hebert, the pivots and holes of which, 

 and the teeth of the escapement had been covered on their sur- 

 faces with fine plumbago, fourteen years before, was taken apart 

 and examined by a committee of the London Society of Arts. The 

 surfaces of plumbago were found, for the most part, entire and per- 

 fectly polished, and a strong magnifying glass discovered not the 

 slightest wear, either in the pivots or the holes. (Trans. Soc. of 

 Arts, 46, p. 48.) — Idem. 



8. Optical Surgery. — M. Maunoir, professor of surgery at Ge- 

 neva, having performed the operation for cataract by extraction upon 

 a man eighty two years of age, weakened by an operation for hernia 

 which he had endured six weeks before, perceived to his regret, that 

 although the pupil remainet of a beautiful black and perfectly intact, 



