428 THE CANADIAN NATURALIST. [Dec. 



which cannot possibly be bathed as other parts are, by the 

 nutritive fluid. What is this atmospheric air ? — this component 

 fluid which all animals must breathe, but which to insects appears 

 to be pre-eminently " the breath of life." Does it contain some- 

 thing more than oxygen, carbonic acid and nitrogen ? Is there 

 not ammonia, and that wonderful substance ozone ? And is it 

 not the carrier of that still more wonderful something, which we 

 call electricity ? It may yet appear, as science advances, that in 

 our respiration, there is something more effected than the mere 

 interchange of oxygen and carbonic acid, with one or two sub- 

 ordinate results ; and that the character of the air we breathe, 

 and the air we live in, is a question of no mean importance to 

 individuals and to communities. Not only do we, like all other 

 terrestrial beings, draw this atmospheric air within our bodies, 

 during the process of respiration, but, like a great ocean, it 

 encompasses us about on every side. And like that deep and 

 dark blue ocean of waters, whose restless vicissitude of storm and 

 calm, is changing our land marks, and modifying our climates ; 

 so this great ocean of air, carries in its bosom the same wonder- 

 ous law of mutation. For, the electrical changes which are 

 constantly taking place in its upper strata, producing sometimes 

 very sudden hygrometric and thermometric changes in the lower, 

 regions, must and do affect the conditions of animal health, to 

 a very great extent. The effect produced by physical alterations 

 in the atmosphere upon the nervous system of animals, and the 

 peculiar influence of atmospheric air upon the bodies of animals 

 (especially upon man) externally, when freely exposed to its 

 action, have not, we think, had that attention from the scientific 

 men that the subject deserves. 



I must not, however, go further with this subject, but will 

 conclude by quoting the eloquent language of Dr. Williams; 

 which langugage he also puts into the form of interrogation. 

 " What can be the meaning of these incomparable pneumatic 

 plexuses, which embrace immediately the very ultimate elements 

 of the solid organs of the body 1 — those minute microscopic air- 

 tubes, which carry oxygen in its gaseous form, unfluidified by 

 any intervening liquid, to the very seats of the fixed solids 

 which constitute the fabric of the organism? The intense 

 electrical and chemical effects, developed by the immediate 

 presence of oxygen at the actual scene of all the nutritive 

 operations of the body, fluid and solid, give to the insect its vivid 



