«^«2 ONT SPONTANEOUS INFLAMMATIONS* 



and 10. The fiVft time the receiver of the machine for fiftlng 

 the charcoal caught fire, and the fecond time it began in the 

 magazine of charcoal, without a fufpicion of any other caufe 

 except that of a fpontaneous inflammation. The different re- 

 ports made on thefe two events, have been inferted in the 

 public journals; but the explanations that were given of them 

 were not fatisfadory. It feems very probable that they were 

 occafioned by fome phofphorus contained in the charcoal; and 

 this explanation has the more weight, becaufe willow (bour- 

 daine), which is ufed at EtTone, as well as in moft other pow- 

 der-manufactories, and which, in many refpecis, deferves the 

 preference over other woods in the preparation of powder, 

 contains phofphoric acid, at leaft that does which grows in our 

 neighbourhood. 



Charcoal from turf begins to be employed in fome domeftic 

 and other operations; but as it is much difpofed to fpontaneous 

 inflammation, its ufe fhould be prevented, or at leaft it fliould 

 be ftored with great precaution. It has happened at Paris and 

 other places, that magazines of this charcoal, which were un- 

 Hieltered, have taken fire by the combined a61ion of the heat 

 and rain. 



10. riiofpTiortis fometimes contained in Charcoal, 



detonation from It may alfo happen that the fmall quantity of phofphorus 

 the phofphorus ^.i^j^], j^ fometimes formed in the carbonization of different 

 m charcoal. ... • ■ i i- 



forts of wood, without uiutmg either with the lime or the pot- 



afh, remains combined with the charcoal, which then does not 

 difengage phofphorated hidrogen gas, nor does it readily in- 

 flame by the fole a6lion of water or of a humid air, but which, 

 by percutiion with falt-petre (nitrate of potafli) may produce a 

 powerful detonation. It is very probable that the three fuc- 

 ceflive explofions which took place in the powder-mill at the 

 manufactory of Vonges, were partly owing to a fimilar caufe. 

 Chaicojl pro- Charcoal has, in general, great influence on the different 

 bab!y one caufe produ6tions of nature and the arts. It is frequently obferved 

 Jity of eold^fhoi-t '" forges and founderies, particularly in thofe of iron, that the 

 irc». produ6ls vary according to the nature of the charcoal employed. 



The bad quality which is fometimes found in iron^ of being 

 brittle when cold, is generally attributed to the phofphoric acid 

 contained in the ores : but fince the fame ore, by the fame pro- 



ceffes. 



