188 FRAGMENTS OF SCIENCE. 



At this season of the year I am usually somewhat shorn 

 of vigour, and therefore not in the best condition for 

 severe experiments ; still I wished to test the matter 

 in my own person. With a respirator which had been 

 in use some days previously, and which was not care- 

 fully packed, I followed a fireman into the smoke, he 

 being provided with a dry-wool respirator. I was 

 compelled to quit the place in about three minutes, 

 while the fireman remained there for six or seven 

 minutes. 



I then tried his respirator upon myself, and found 

 that with it I could not remain more than a minute in 

 the smoke ; in fact the first inhalation provoked 

 coughing. 



Thinking that Captain Shaw himself might have 

 lungs more like mine than those of his fireman, I pro- 

 posed that we should try the respirators together ; 

 but he informed me that his lungs were very strong. He 

 was, however, good enough to accede to my request. Be- 

 fore entering the den a second time I repacked my respi- 

 rator, with due care, and entered the smoke in company 

 with Captain Shaw. I could hear him breathe long 

 slow inhalations ; his labour was certainly greater than 

 mine, and after the lapse of seven minutes I heard him 

 cough. In seven and a half minutes he had to quit the 

 place, thus proving that his lungs were able to endure 

 the irritation seven times as long as mine could bear it. 

 I continued in the smoke, with hardly any discomfort, 

 for sixteen minutes, and certainly could have remained 

 in it much longer. The advantage arising from the 

 glycerine was thus placed beyond question. 



During this time I was in a condition to render 

 very material assistance to a person in danger of suffo- 

 cation. 



