BY THE PEESIDENT. 
141 
impurities which, convert a cheerless enough cloud on the ground 
into a choking and blinding fog. Beyond this man feels so power¬ 
less over the air he breathes, that for the most part he treats its 
rich materials for thought with a shrug or at least in a non possumus 
spirit. Added to all this, varying conditions of the atmosphere do 
unquestionably produce effects on health that at present we cannot 
explain ; effects that are scarcely referable to dryness or moisture, 
coldness or warmth, greater or less volume, or other known con¬ 
ditions. There is still much in connection with the air we breathe 
that is mysterious. It may however be worthy of notice that the 
scientific chemist has long suspected that some of the effects of 
vitiated air, and certain effects of normal air, are due to organic 
matter rather than to alterations in the proportions of natural 
constituents, a suspicion confirmed recently by the microbiologist, 
who, while finding abundance of those minute forms of life termed 
microbes in the atmosphere of cities and the air of a sick room, 
finds fewer in the air of the plains and scarcely any in the air of 
mountains a few thousands of feet high. "What may he the exact 
connection between the presence of aerial microbes and the health 
or ill-health of man remains to he discovered—a discovery, we may 
add, that will certainly, sooner or later, he made : for it would 
seem as if all such so-called secrets of nature were merely truths 
veiled by the haze of our own imperfect understandings; such a 
haze as always disappears before the earnest, patient, untiring, 
humble, skilful seeker after truth. 
THE CLOTHING WE WEAR. 
From the extremes of heat and cold, even the healthy frame 
needs the protection of clothes. How, natural law requires that 
these fabrics be bad conductors of heat; garments that in summer 
shall allow the minimum of the sun’s heat to pass through to the 
already over-warm body, and in winter shall allow the minimum 
of the warmth of the body to escape to the outer cold air. Oddly 
enough, the best non-conductor is air itself; but it must he non¬ 
moving, or very slowly moving, air; so that if we can manage to 
enclose a sheet of air between appropriate sheaths, or imprison it 
in an appropriate net, we shall have a typical garment both for 
summer and winter wear. Such a garment is found in the woollen 
clothes or flannel of the cricketer’s summer suit, and the woollen 
dress or overcoat of winter. A blanket is a similar covering, of 
world-wide appreciation, against the escape of warmth from the 
body during a cold night. An eider-down quilt is a similar 
air-enclosing shield of wonderful lightness. These fabrics are 
