THE YOUNG SCIENTIST. 
107 
Do not hitch the body in any way ; the 
limbs must do all the work. Keep the 
neck stiff, and make no effort to raise the 
head above the surface of the water be- 
yond the motion of arms and legs. The 
weight of the head is diminished consider- 
ably when it rests on or in the water. The 
body and legs should be level, the head 
being very slightly raised. 
Many swimmers experience difficulty in 
regulating the breathing. There should 
be no difficulty at all in breathing as regu- 
larly in the water as when walking on 
terra flrma, once the first disagreeable 
feeling in learning it has been got over. 
The fastest and best of our living swim- 
mers have the mouth and nostrils im- 
mersed in the water for at least two-thirds 
of the time they are swimming. This, 
along with the improved side and over- 
hand stroke, accounts for the very fast 
swimming that is being performed, at the 
matches especially. The mouth and nos- 
trils lie deepest in the water at the begin- 
ning of the stroke— that is, when the 
hands are being stretched in front, while 
they are raised just above the level of the 
water as the arms are brought around in 
the second position. Therefore, to breathe 
regularly the swimmer should exale or 
partly empty the lungs at once. This is 
easily done, although the mouth is under 
water. The lungs are then filled in an 
instant, quite easily, during the second 
part of the stroke. Be sure to breathe 
regularly every stroke, and never com- 
pletely empty the lungs. Care must at 
first be taken not to open the mouth too 
soon, or water instead of air will be taken 
in. Presence of mind is essential to the 
learner. It is also indispensable to the 
best swimmer. Let the swimmer always | 
bear in mind that, no matter how tired he j 
may be, if not actually cramped, by turn- 1 
ing on his back the slightest movement ! 
of legs or arms will support him on the 
surface of the water ; or, take a good long 
breath, expand the chest, keep the head , 
well back, and lie perfectly still ; then he 
will have time to consider what had best 
be done. In all likelihood he will be suf- 
ficiently rested to resume the journey 
back again, if help has not arrived. One 
thing all swimmers should guard against : 
that is, not to allow themselves to go too 
far out with the current when the tide is 
ebbing. The best swimmers will find it 
hard work mailing headway against some 
currents, xlnother error to be guarded 
against is remaining in the water too long 
at a time. To practice swimming with a 
view to benefit by its healthful effects, 
the stay in the water ought not to be pro- 
longed beyond from eight to ten minutes. 
Marvels of Pond Life. 
ONE of the most interesting books in 
the library of the amateur micro- 
scopist is the " Marvels of Pond Life," by 
Mr. Henry J. Slack, late secretary to the 
Eoyal Microscopical Society. This book 
deals entirely with microscopic forms of 
animal life, and the common experience 
of all microscoi)ists confirms the asser- 
tion made by Dr. Goring, that the most 
fascinating objects are living creatures of 
sufficient dimensions to be easily under- 
stood with moderate magnification ; and 
in no way can objects of this description 
be so readily obtained, as by devoting an 
occasional hour to the examination of the 
little ponds which are accessible from 
almost any situation. A complete volume 
of pond lore would not only be a bulky 
book, but its composition would overtask 
all the philosophers of our day. In good 
truth, a tea-spoonful of water from a 
prolific locality often contains a variety 
of living forms, every one of which de- 
mands a profound and patient study, if 
we would know but a few things concern- 
ing it. 
There is an irresistible charm in the 
effort to trace beginnings in nature. We 
know that we can never succeed; that 
each discovery, which conducts back 
towards some elementary law or principle, 
only indicates how much still lies behind 
it : but the geologist nevertheless loves to 
search out the first or oldest traces of life 
upon our globe ; and so the microscopist 
delights to view the simplest exhibitions 
of structures and faculties, which reach 
their completion in the frame and mind 
of man. That one great plan runs through 
the whole universe is now universally ac- 
cepted truth, andVhen applied to physi- 
