Protection of Persons from Fire. i15 
after it may have been extinguished by the wire gauze, there must be 
imminent danger of asphyxia; and that if no difficulty of breathing 
ensues, a purer air must find access to the men, and this he con- 
ceives may occur in several ways. 
1. It is certain that the men have not their heads constantly in the : 
flame, which we know moves with the gentlest current, and thus af* 
fords moments favorable for respiration. 
2. Admitting that the men remain too long in the Hames to breathe 
freely, we must then conceive that fresh air may rise between the two 
tissues not in contact, and thus supply the respiration. Besides, it is 
not difficult to hold one’s breath thirty, sixty, or even more seconds, 
and though we do not think that the firemen resorted to this in pass- 
ing along the hedges of flame, the short time requisite to walk ten 
yards renders it possible. . 
But although in the open air, or in a free space, respiration may be 
effected without danger, it is certainly to be feared that ina confined 
situation, filled with smoke, which it is so common to meet with at 
fires, it would not be possible to breathe freely, though protected by 
the armor. Would it not be advisable then to provide a portable re- 
servoir of fresh air, or a flexible tube descending from the mouth to 
the floor, where the purest air is generally to be found. The reporter 
sists on this point, for nothing so much interferes with respiration as 
adense smoke. It would be well for firemen to exercise themselves, 
like divers, in holding their breath. 
mianthus is found more abundantly, especially in Corsica, than it 
Was formerly. supposed ; and since Madame Lena Perpenti of Como 
has succeeded in making various qualities of tissue, and even lace, of 
this material, it cannot be doubted that this mineral may be used for 
the various operations of spinning and weaving, but it must always 
bear too high a price to admit of extensive applications. Hence 
Woollen cloth. properly prepared is to be preferred, and when well 
M™ptegaated with sal ammoniac and borax it does not take fire; and 
may even be calcined without communicating combustion, and is also 
a slow conductor of heat. In this latter respect it has even the ad- 
Vantage of amianthus, as has been shewn by M. Hourens. There- 
fore, in point of economy, of facility of preparation, of convenient 
use, of lightness, and of slower conducting power, wool is preferable 
‘0 amianthus,—and its resistance to flame, though incomparably less 
than that of the mineral, is nevertheless great enough to answer as a 
Substitute for the latter in almost all the circumstances of ordinary fires. 
