in a Flour- Warehouse . 
59 
damp, and had not any sensible degree of heat, there 
should not be any fermentation in it, and consequently no 
inflammable air should be produced : to this I answer, 
First. That flour is never entirely free from humidity, 
as is evidently shewn by distillation. 
Secondly. That although the degree of heat was not 
so great as to set free inflammable air by fermentation, a 
sufficient quantity was set free, by what may he called 
a mechanical mean, to inflame upon the contact of light $ 
and to disengage, at the same time, all that which com- 
municated with the atmospheric air. 
Thirdly. We must recollect that flour also furnishes 
alkaline inflammable air, which is produced from the 
glutinous vegeto- animal part of the corn ; and we know 
that this kind of inflammable air is of a very active na- 
ture. 
After having described this singular event, I shall beg 
leave to collect together, in this place, all the known 
facts respecting spontaneous inflammations produced by 
different substances. A circumstantial account of these 
phenomena cannot but be very interesting to those con- 
cerned in government ; not only as it may tend to pre- 
vent the unhappy accidents which result from them, but 
also as it may sometimes hinder the suspicion and perse- 
cution of innocent persons, on account of events which 
are produced merely by natural causes. 
I shall not mention the inflammations caused by light 
ning, by subterraneous fires, and by other meteors ; they 
are not of the nature of those of which I mean to speak, 
but I shall not pass over in silence the spontaneous com- 
bustions of human bodies. Though events of this kind 
are very rare, yet we have some examples of them re- 
corded in the Philosophical Transactions, and in the 
memoirs of the academies of Paris and of Copenhagen. 
It is there related, that an Italian lady (the countess 
