316 FRAGMENTS OF SCIENCE. 



the body epidemic disease. If this be so, then disease can 

 be warded off by carefully-prepared filters of cotton-wool. 

 I should be most willing to test their efficacy in my own 

 person. But apart from all doubtful applications, it is per 

 fectly certain that various noxious trades in England may 

 be rendered harmless by the use of such niters. I have 

 had conclusive evidence of this from people engaged in 

 such trades. A form of respirator devised by Mr. Garrick, 

 a hotel proprietor in Glasgow, in which inhalation and ex 

 halation occur through two different valves, the one per 

 mitting the air to enter through the cotton-wool, and the 

 other permitting the exit of the air direct into the atmos 

 phere, is well adapted for this purpose. But other forms 

 might readily be devised. 



Fireman s Respirator. 



Smoke is often the fireman s greatest obstacle in his 

 efforts to save life ; I thought, therefore, of inventing a res 

 pirator for the use of firemen. Schroeder was the first to 

 use cotton-wool as a filter. To catch the atmospheric 

 germs, M. Pouchet employed a film of adhesive glycerine 

 spread upon glass ; while Dr. Stenhouse turned charcoal to 

 important account in respirators. By a combination of all 

 three a respirator of peculiar efficacy is obtained. For the 

 smoke of dried leaves the cotton-wool alone was found an 

 adequate protection ; but for the far more pungent smoke 

 of resinous deal it was found totally inadequate. At the 

 suggestion of a friend I moistened the wool with glycerine, 

 and found it a great improvement. It was the notion of 

 Pouchet in another form. Still about five minutes in dense 

 smoke was all that could be endured. I then associated 

 fragments of charcoal with the moistened cotton ; the effect 

 was excellent. 1 Armed with a respirator of this kind, one 

 1 Mr. Ladd, of Beak Street, makes these respirators. 



