M. Aldini's Incombustible Dresses. 207 



I have judged from my own feelings, in supposing that even 

 trifles connected with such a man would have an interest for 

 the cultivators, especially of chemical science ; and should this 

 paper ever meet the eye of Berzelius, I trust he will forgive 

 me for teaching my countrymen to regard him as equally ami- 

 able in private life as they have long considered him distin- 

 guished in the chemical world. 



PoiiTOBELLo, ^th January 1830. 



Art. II. — Account of the apparatus and hicombustible Dresses 

 invented by M. Aldini Jar Preserving the Body from the 

 Action of Fire *. 



J. HE incombustible dresses of M. Aldini consist of two gar- 

 ments, the one being composed of a thick fabric of amiantlius, 

 or asbestos, or of wool rendered incombustible by impregnation 

 with a saline substance ; and the other of a fabric of wire 

 gauze, which is placed without the first. 



It is well known, from the fine experiments of Sir Humphry 

 Davy, that wire gauze, with the meshes sufficiently narrow, 

 completely intercepts flame, even when it is impelled by a 

 great pressure, as in the case of an explosive mixture. This 

 effect is produced by the cooling of the flame caused by the 

 metal, and consequently cannot take place unless this last ex- 

 perience a rise of temperature proportional to the time that 

 the flame continues in contact with the wire gauze. 



This metallic garment, the mass of which is very inconsi- 

 derable, would not of itself be efficacious in defending the 

 body from the action of heat ; but the amianthus, or the im- 

 pregnated woollen dress, opposes itself by its thickness and its 

 feeble conducting power to the arrival of the heat at the sur- 

 face of the body, and along with the metallic gauze it forms 

 an impenetrable shelter during a time which ought to be suf- 

 ficient for the operations of the firemen. The woollen dress 

 is indispensable, and even more important than the metallic 



^ This article is the substance of M. Gay-Lussac's Report to the Aca- 

 demy of Sciences of Paris, printed in the Ann. de Ckimie, torn. xlii. p. 214. 



