VENTILATION. 35 



cannot long be maintained without its agency. The Black 

 Hole, at Calcutta is an admonition in favor of proper or 

 sufficient ventilation. 



The horses which were confined only for a few hours on 

 board of ships in the military expeditions, sent out by the 

 British government to Quiberon and Varna, when the 

 storm compelled the hatches tc be put down, were almost 

 invariably affected with glanders. We mention these 

 occurrences, because Mr. A. B. Allen, editor of Stewart's 

 book, affects to doubt that bad ventilation could produce 

 those affections amongst the horses on board, by stating as 

 his opinion, that the animals were diseased when put on the 

 ships. Mr. Stewart was right in his remarks on the cause 

 of the sickness ; and Mr. Allen has simply shown, that he 

 is incapable of tracing effect to its cause when he penned 

 his assertion, doubting the opinion of a man who, in his 

 day, had but few equals as a veterinary surgeon and 

 writer. 



Moreover, the views expressed by Mr. Stewart thirty 

 years ago, are substantiated by science and experience at 

 the present day. The analyses of impure and pure air have 

 shown us a difference, that few persons, even in our time 

 have anticipated. The fact is, that the condensed air of a 

 crowded place where animals are kept, gives a deposit, 

 which, if allowed to remain on the walls and fixtures for a 

 few days, forms a solid, thick, glutinous mass, having a 

 strong odor of animal matter, which, if examined by the 

 microscope, is seen to undergo a remarkable change, by its 

 4 



