416 



SCIENCE 



[N. S. Vol. XLIX. No. 1270 



the arrangemettt of one of them. Externally, it 

 had the appearance of a small feneing-mask of 

 wire gauze, covering the face from the chin ■up- 

 wards to the bridge of the nose, but leaving the 

 eyes and forehead free. It consisted, essentially, 

 of two plates of wire gauze, separated from each 

 other by a space of about one fourth or one 

 eighth of an inch, so as to form a small cage filled 

 with small fragments of charcoal. The frame of 

 the cage was of copper, but the edges were made 

 of soft lead, and were lined with velvet, so as to 

 admit 'of their being made to fit the cheeks 

 tightly ?Jid inclose the mouth and nostrils. By 

 this arrangement, no air could enter the lungs 

 without passing through the wire gauze and tra- 

 versing the charcoal. An aperture is provided 

 with a screw or sliding valve for the removal and 

 replenishment of the contents of the cage, which 

 consist of the siftings or riddlings of the lighter 

 kinds of wood charcoal. The apparatus is at- 

 tached to the face by an elastic band passing over 

 the crown of the head and strings tying behind, 

 as in the case of the ordinary respirator. The im- 

 portant agent in this instrument is the charcoal, 

 which has so remarkable a power of absorbing 

 and destroying irritating and othervrise irrespira- 

 ble and poisonous gases or vapors that, armed with 

 the respirator, spirits of hartshorn, sulphuretted 

 hydrogen, hydrosulphuret of ammonia and chlo- 

 rine may be breathed through it with impunity, 

 though but slightly diluted with air. This result, 

 first obtained by Dr. Stenhouse, has been verified 

 by those who have repeated the trial, among 

 others by Dr. Wilson, who has tried the vapors 

 named above on himself and four of his pupils, 

 who have breathed them with impunity. The ex- 

 planation of this remarkable property of charcoal 

 is two-fold. It has long been known to possess the 

 power of condensing into its pores gases and 

 vapors, so that if freshly prepared and exposed 

 to these, it absorbs and retains them. But it has 

 scarcely been suspected till recently, when Dr. 

 Stenhouse pointed out the fact, that if charcoal 

 be allowed to absorb simultaneously such gases as 

 sulphuretted hydrogen and air, the oxygen of this 

 absorbed and condensed air rapidly oxidizes and 

 destroys the accompanying gas. So marked is this 

 action, that if dead animals be imbedded in a 

 layer of charcoal a few inches deep, instead of 

 being prevented from decaying as it has Mtherto 

 been supposed that they would be by the sup- 

 posed antiseptic powers of the charcoal, they are 

 found by Dr. Stenhouse to decay much faster, 

 whilst at the same time, no offensive effluvia are 



evolved. The deodoriziug powers of charcoal are 

 thus established in a way they never have been 

 before; but at the same time it is shown that the 

 addition of charcoal to sewage refuse lessens its 

 agricultural value contemporaneously with the 

 lessening of odor. From these observations, which 

 have been fully verified, it appears that by strew- 

 ing charcoal coarsely powdered to the extent of a 

 few inches, over church-yards, or by placing it in- 

 side the coflins of the dead, the escape of noisome 

 and poisonous exhalations may be totally pre- 

 vented. The charcoal respirator embodies this 

 important discovery. It is certain that many of 

 the miasma, malaria and infectious matters which 

 propagate disease in the human subjects, enter 

 the body by the lungs, and impregnating the 

 blood there, are carried with it throughout the 

 entire body, which they thus poison. These 

 miasma are either gases and vapors or bodies 

 which, like fine light dust, are readily carried 

 through the air; moreover, they are readily de- 

 stroyed by oxidizing agents, which convert them 

 into harmless, or at least non-poisonous sub- 

 stances, such as water, carbonic acid and nitrogen. 

 There is every reason, therefore, for believing that 

 charcoal will oxidize and destroy such miasma as 

 effectually as it does sulphuretted hydrogen or 

 hydrosulphuret of ammonia, and thus prevent 

 their reaching and poisoning the blood. The in- 

 tention accordingly is that those who are exposed 

 to noxions vapors, or compelled to breathe in- 

 fected atmospheres, shall wear the charcoal re- 

 spirator, with a view to arrest and destroy the 

 volatile poisons contained in these. Some of the 

 non-obvious applications of the respirator were 

 then referred to: 



1. Certain of the large chemical manufacturers 

 in London are now supplying their workmen with 

 the charcoal respirators as a protection against 

 the more irritating vapors to which they are ex- 



2. Many deaths have occurred among those em- 

 ployed to explore the large drains and sewers of 

 London from exposure to sulphuretted hydrogen, 

 etc. It may be asserted with confidence that fatal 

 results from exposure to the drainage gases will 

 cease as soon as the respirator is brought into use. 



3. In districts such as the Campagna of Home, 

 where malaria prevails and to travel during night 

 or to sleep in which is certainly followed by an 

 attack of dangerous and often fatal ague, the 

 wearing of the respirator even for a few hours 

 may be expected to render the marsh poison harm- 

 less. 



