CHAPTER IV. 



RESPIRATION OF THE LARVA. 



WE well know/ from the various melancholy acci- 

 dents which have taken place, that unless human 

 beings have a constant supply of pure fresh air they 

 must perish. Many years ago, a number of unfortu- 

 nate persons were shut up in a narrow cell, called 

 the Black Hole, at Calcutta, where they could 

 scarcely find room to stand, much less obtain air to 

 breathe. In one night the greater part of them died. 

 More recently, as some poor Irish were being con- 

 veyed in a steamer in stormy weather, the captain, 

 out of prudence and mistaken kindness, ordered the 

 hatches to be all battened down, so that fresh air 

 was prevented from getting in. A shocking spec- 

 tacle was beheld soon afterwards: in the close, 

 suffocating cabin lay a number of dead bodies, of 

 men, women, and children, all destroyed by the 

 want of air. Now, precisely the same fatal results 



