•7uly Vo, 1871.] 
THE PHARMACEUTICAL JOURNAL AND TRANSACTIONS. 
47 
I 
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 leam 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 sub¬ 
stance 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 unen¬ 
durable. 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 when the condensing body is very porous, or in a 
fine state of division, the force of condensation may pro¬ 
duce very remarkable effects. Thus, a clean piece of 
platinum-foil placed in a mixture of oxygen and hydro¬ 
gen so squeezes the gases together as to cause them to 
combine ; and if the experiment be made with care, the 
heat of combination may raise the platinum to bright 
redness, so as to cause the remainder of the mixture to 
■explode. The promptness of this action is greatly aug¬ 
mented by reducing the platinum to a state of fine divi¬ 
sion. A pellet of “ spongy platinum,” for instance, 
plunged into a mixture of oxygen and hydrogen, causes 
the gases to explode instantly. In virtue of its extreme 
porosity, a similar power is possessed by charcoal. It is 
not strong enough to cause the oxygen and hydrogen to 
combine like the spongy platinum, but it so squeezes the 
more condensable vapours together, and also acts with 
such condensing power upon the oxygen of the air, as to 
■bring both within the combining distance, thus enabling 
The oxygen to attack and destroy the vapours in the 
pores of the charcoal. In this way, effluvia of all kinds 
may be virtually burnt up, and this is the principle of 
the excellent charcoal respirators invented by Dr. Sten- 
house. Armed with one of these, you may go into the 
foulest-smelling places without having your nose offended. 
Some of you will remember Dr. Stenhouse lecturing in 
this room with a suspicious-looking vessel in front of 
the table. That vessel contained a decomposing cat. 
It was covered with a layer of charcoal, and nobody 
knew until told of it what the vessel contained. 
I may be permitted in passing to give my testimony 
as to the efficacy of these charcoal respirators in providing 
warm air for the lungs. Not only is the sensible heat 
■of the breath in part absorbed by the charcoal, but the 
considerable amount of latent heat which accompanies 
the aqueous vapour from the lungs is rendered free by the 
condensation of the vapour in the pores of the charcoal. 
Each particle of charcoal is thus converted into an inci- j 
pient ember, and warms the air as it passes inwards. 
But while powerful to arrest vapours, the charcoal 
respirator is ineffectual as regards smoke. The particles 
get freely through the respirator. In a series of them 
tested downstairs, from half a minute to a minute was 
the limit of endurance. This might be exceeded by; 
tFaraday’s method of emptying the lungs completely, 
and then filling them before going into a smoky atmo¬ 
sphere. In fact, each solid smoke particle is itself a bit 
; of charcoal, and carries on it, and in it, its little load of 
| irritating vapours. It is this, far more than the particles 
1 of carbon themselves, that produces the irritation. 
Hence two causes of offence are to be removed: the 
carbon particles which convey the irritant by adhesion 
; and condensation, and the free vapour which accom¬ 
panies the particles. The moistened cotton-wool I knew 
would arrest the first, fragments of charcoal I hoped 
would stop the second. In the first fireman’s respirator, 
Mr. Carrick’s arrangement of two valves, the one for 
inhalation, the other exhalation, are preserved. But 
the portion of it which holds the filtering and absorbent 
substances is prolonged to a depth of four or five inches. 
On the partition of wire gauze at the bottom of the 
' space "which fronts the mouth, is placed a layer of cot¬ 
ton-wool, moistened with glycerine; then a thin layer 
of dry wool; then a layer of charcoal fragments; a 
second thin layer of dry cotton wool, succeeded by a 
layer of fragments of caustic lime. The succession of 
the layers may be changed without injury to the action. 
A wire-gauze cover keeps the substances from falling 
out of the respirator. In the densest smoke that we 
have hitherto employed, the layer of lime has not been 
found necessary; in a flaming building, indeed, the 
mixture of air with the smoke never permits the car¬ 
bonic acid to become so dense as to be irrespirable. But 
: in a place where the gas is present in undue quantity, 
J the fragments of lime would materially mitigate its 
action. 
In a small cellar-like chamber downstairs, with a 
stone flooring and stone walls, the first experiments 
j were made. We placed three furnaces containing re- 
; sinous pine-wood, lighted the wood, and placing over it 
a lid which prevented too brisk a circulation of the air, 
generated dense volumes of smoke. With our eyes pro¬ 
tected by suitable glasses, my assistant and I have re¬ 
mained in this room for half an hour and more, when 
the smoke was so dense and pungent that a single inha¬ 
lation through the undefended mouth would be per¬ 
fectly unendurable ; and we might have prolonged our 
stay for hours. Having thus tar perfected the instru¬ 
ment, I wrote to Captain Shaw, the chief officer of the 
Metropolitan Fire Brigade, asking him whether such a 
respirator would be of use to him. His reply was 
prompt; it would be most valuable. He had, however, 
made himself acquainted with every contrivance of the 
kind in this and other countries, and had found none of 
them of any practical use. He offered to come and test 
it here, or to place a room at my disposal in the City 
At my request he came here, accompanied by three of 
his men. Our small room was filled with smoke to their 
entire satisfaction. The three men went successively 
into it, and remained there as long as Captain Shaw 
wished them. On coming out they said that they had 
not suffered the slightest inconvenience; that they could 
have remained all day in the smoke. Captain Shaw then 
tested the instrument with the same result. From that 
hour the greatest interest has been taken in the perfect¬ 
ing of the instrument by Captain Shaw himself. He 
has attached to the respirator suitable hoods. The 
real problem is practically solved, and I can only sav 
that if a tithe of the zeal, intelligence and practical 
skill were bestowed on the cotton-wool respirator that 
Captain Shaw has devoted to the fireman s respirator 
the sufferings of many a precious life might be spared, 
and its length augmented.*' 
The lecture was concluded as follows :—“Thus have 
we been led from the actinic decomposition of vapours 
* Mr. Ladd has also proposed a form of mouthpiece whiclx 
promises well, and Mr. Cottrell has attached to it an oicli- 
dinary fencing-mask. This will probably he the term ot 
apparatus finally adopted. 
