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In fact a hundred obvious cases might be cited, and others 
that are not obvious might be added to them. We should 
not, for example, think that printing implied labours 
where the use of cotton-wool respirators might come into 
play ; but I am told that the dust arising from the sorting 
of the type is very destructive of health. I went sometime 
ago into a manufactory in one of our large towns, where 
iron vessels are enamelled by coating them with a mineral 
powder, and subjecting them to a heat sufficient to fuse 
the powder. The organisation of the establishment was 
excellent, and one thing only was needed to make it 
faultless. In a large room a number of women were en- 
gaged covering the vessels. The airwas Jaden with the 
fine dust, and their faces appeared as white and blood- 
less as the powder with which they worked. By the use 
of cotton-wool respirators these women might be caused to 
breathe air more free from suspended matters than that 
of the open street. Over a year ago I was written to by 
a Lancashire seedsman, who stated that during the seed 
season of each year his men suffered horribly from irritation 
and fever, so that many of them left his service. He 
asked me could I help him, and I gave him my advice. 
At the conclusion of the season this year he wrote to me 
that he had simply folded a little cotton-wool in muslin, 
and tied it in front of the mouth ; that he had passed 
through the season in comfort and without a single com- 
plaint from one of his men. 
The substance has also been turned to other uses. An 
invalid tells me that at night he places a little of the wool 
before his mouth, slightly moistening it to make it adhere ; 
that he has thereby prolonged his sleep, abated the irri- 
tation of his throat, and greatly mitigated a hacking cough 
from which he had long suffered. In fact, there is no 
doubt that this substance is capable of manifold useful 
applications, 
it: that it became wet and heated by the breath. While 
I was casting about for a remedy for this, a friend for- 
warded to me from Newcastle a form of respirator invented 
by Mr. Carrick, an hotel-keeper at Glasgow, which meets 
the case effectually, and, by a slight modification, may be 
caused to meet it perfectly. The respirator, with its back 
in part removed, is shown in Fig. 1. It consists of the 
space under the partition of wire-gauze g 7, intended by 
Mr. Carrick for ‘ medicated substances,” and which may 
be filled with cotton-wool. The mouth is placed against 
the aperture 0, which fits closely round the lips, and the 
air enters the mouth through the cotton-wool, by a light 
valve v, which is lifted by the act of inhalation. During 
exhalation this valve closes ; another breath escapes by a 
second valve, v’, into the open air. The wool is thus kept 
dry and cool ; the air in passing through it being filtered 
of everything it holds in suspension.* 
We have thus been led by our first unpractical experi- 
ments into a thicket of practical considerations. In taking 
the next step, a personal peculiarity had some influence | 
upon me. The only kind of fighting in which I take the 
least delight, is the conflict of man with nature. I like to 
see a man conquer a peak or quench aconflagration. I 
remember clearly the interest I took twenty years ago in 
seeing the firemen of Berlin contending for mastery 
with a fire which had burst out somewhere near the Bran- 
denburger Thor ; and I have often experienced the same 
interest in the streets of London. Admiring as I do the 
energy and bravery of our firemen, and having heard that 
smoke was a greater enemy to them than flame itself, the 
desire arose of devising a fireman’s respirator. But before 
I describe what has been done in this direction, let me 
draw your attention to the means hitherto employed to 
enable a man to live in dense smoke. Thanks to the 
courtesy of Capt. Shaw, I am enabled to show you the | 
action of the ‘“smoke-jacket,” known abroad as the 
“ Appareil Paulin,” from its supposed inventor. The 
jacket is of pliable cowhide. It has arms and a hood, with 
* Dbr. Ladd, of Beak Street. sells these respirators. 
NATURE 
An objection was urged against the use of 
| [Fune 15,1871 

eye-glasses. With straps and buckles the jacket is tied 
round the wrists and waist, and a strap which passes 
between the legs prevents it from rising. On the left side 
of the jacket is fixed a screw, to which the ordinary hose of 
the fire-engine is attached, and through the hoseair instead 
of water is urged into the space between the fireman’s body 
and the jacket. It becomes partially inflated, but no pressure 
of any amount is attainable, because the air, though some- 
what retarded, escapes with tolerable freedom from the 
wrists and waist. Hence the fireman, when his hose is long 
enough, can deliberately walk into the densest smoke or 
foulest air. But you see the use of the smoke-jacket 
necessitates the presence of several men ; it also implies 
the presence of an engine. A single man could make no 
use of it, nor indeed any number of men without a pump- 
ing engine. Its uses are thus summed up in a communi- 
cation addressed to me by Captain Shaw :— 
“ This smoke-jacket is very useful for extinguishing fires 
in vaults, stopping conflagrations in the holds of ships, 
and penetrating wells, quarries, mines, cesspools, &c.— 
any places, in short, where the air has become unfit for 
respiration, 
“The special advantages of this jacket are its great 
simplicity, its facility for use, and the rapidity with which 
it can be carried about and put on; but its drawback is 
that it requires the use of an engine or air-pump, and 
consequently is of no service to one man alone. For this 
latter reason smoke-jackets, although very effective for 
enabling us to get into convenient places for extinguishing 
fires, have very rarely proved of any avail for saving life.” 
Now it is that very want that I thought ought to be 
supplied by a suitable respirator. Our fire-escapes are 
each in charge of a single man, and I wished te be able 
to place it in the power of each of those men to penetrate 
through the densestsmoke into the recesses ofa house, and 
there to rescue those who would otherwise be suffocated 
or burnt. I thought that cotton wool, which so effectually 
arrested dust, might also be influential in arresting smoke. 
It was tried ; but, though found soothing in certain gentle 
kinds of smoke, it was no match for the pungent fumes 
of a resinous fire, which we employ in our experiments in 
the laboratory, and which, I am gratified to learn from 
Captain Shaw, evolves the most abominable smoke with 
which he is acquainted. I cast about for an improvement, 
and in conversing on the subject with my friend Dr. 
Debus, he suggested the use of glycerine to moisten the 
wool, and render it more adhesive. In fact, this very 
substance had been employed by the most distinguished 
advocate of the doctrine of spontaneous generation, M. 
Pouchet, for the purpose of catching the atmospheric 
germs. He spread a film of glycerine on a plate of 
glass, urged air against the film, and examined the 
dust which stuck to it. The moistening of the cotton-wool 
with this substance was a decided improvement ; still the 
respirator only enabled us to remain in dense smoke for 
three or four minutes, after which the irritation {became 
unendurable. Reflection suggested that in combustion so 
imperfect as the production of dense smoke implies, there 
must be numerous hydrocarbons produced which, being 
in a state of vapour, would be very imperfectly arrested 
by the cotton wool. These in all probability were the 
cause of the residual irritation; and if these could be 
removed, a practically perfect respirator might possibly be 
obtained. 
I state the reasoning exactly as it occurred to my mind. 
Its result will be anticipated by many present. All bodies 
possess the power of condensing in a greater or less 
degree gases and vapours upon their surfaces, and whea 
the condensing body is very porous, or ina fine state of 
division, the force of condensation may produce very re- 
markable effects. Thus, a clean piece of piatinum-foil 
placed in a mixture of oxygen and hydrogen so squeezes 
the gases together as to cause them to combine; and if 
| the experiment be made with care, the heat of combina- 


