generally attributed to tlieir fins, is almost 
wholly owing to their muscles, and the equi- 
poise of their air-bladder. That the use of 
the pectoral and ventral fins is to keep the 
fish steady and upright in the water, is evi- 
dent from the consequences of their loss : 
if they are cut off, and the fish put again 
into the water, it cannot continue in its na- 
tural erect posture, but staggers about and 
rolls from side to side. The fins of the 
back and anus are also of great use to the 
keeping the creature in its natural posi- 
tion, as is easily seen by cutting them off, 
and observing the motions of the fish after- 
wards. Though a great deal depends on 
the motion of the muscles of the several 
parts of the body, in the swimming of the 
fish, yet the tail, and those muscles which 
move the lower part of the body, to which 
it is affixed, are the great instruments by 
which their swift motions in the water are 
performed. The moving the tail, and that 
part of the body to which it adheres, back- 
ward and forward, or sideways any one 
way, throws the whole body of the fish 
strongly the contrary way ; and even in 
swimming strait forward, the motion and 
direction are both greatly assisted by the 
vibrations of this part, as may be expe- 
rienced in the motion of a boat, which, 
when impelled forward, may be firmly guid- 
ed by means of an oar held out at its stern, 
and moved in the water as occasion directs. 
The dorsal muscles, and those of the lower 
part of the body between the anus and tail, 
are the principal that are used in the mo- 
tion of this part, and these are therefore 
the most useful to the fish in swimming. 
The muscles of the belly seem to have their 
principal use in tlie contracting the belly 
and the air-bladder. They have been sup- 
posed of use to move the belly-fins; but 
there are too many of them for .such a pur- 
pose, and these fins have each its peculiar 
muscle fully sufficient to the business. The 
use of the tail in swimming is easily seen, 
by cutting it off, and committing the fish to 
the water without it, in which case it is a 
most helpless creature. 
Brutes swim naturally, but men attain 
this art by practice and industry : it consists 
principally in striking alternately with the 
hands and feet; which, like oars, row a per- 
son forward : he must keep his body a little 
oblique, that he may the more easily erect 
his head, and keep his mouth above water. 
We shall here insert some maxims on the 
art of swimming that may be useful, and 
SWIMMING. 
which are said to liave been written by the 
late Dr. Franklin. 
1. That though the tegs, arms, and’head, 
of a human body, being solid parts, are spe- 
cifically something heavier than fresh water, 
yet the trunk, particularly the upper part, 
from its hollowness, is so much lighter than 
water, as that the whole of the body, taken 
together, is too light to sink wholly under 
water, but some part will remain above, 
until the lungs become filled with water; 
which happens from drawing water into 
them instead of air, when a person, in the 
fright, attempts breathing while the month 
and nostrils are under water. 2. That the 
legs and arms are .specifically lighter than 
salt water, and will be .supported by it, so 
that a human body would not sink in salt 
water, though the lungs were filled as above, 
but from the greater specific gravity of the 
head. 3. That therefore a person throwing 
himself on his back in salt water, and ex- 
tending his arms, may easily he so as to 
keep his mouth and nostrils free for breath- 
ing; and, by a small motion of his hands, 
may prevent turning, if he should perceive 
any tendency to it. 4. Tliat in fresh wa- 
ter, if a man tlirows himselt on his back, 
near the surface, he cannot long continue in 
that situation, but by proper action of his 
hands, on the water. If he uses no such 
action, the legs and lower part of the body 
will gradually sink till he comes into an up- 
right position, in which he will continue 
suspended, the hollow of the breast ^keep- 
ing the head uppermost. 5. But if in thi.s 
erect position, the head is kept upiight 
above the shoulders, as when we stand on 
the ground, the immersion will, by the 
weisht of that part of the head that is out 
of water, reach above the mouth and nos- 
trils, perhaps a little above the eyes, so that 
a man cannot long remain suspended in wa- 
ter with his head in that position. 6. The 
body continuing suspended as before, and 
upright, if the head be leaned quite back, 
so that the face looks upwards, all the back 
part of the head being then under water, 
and its weight consequently in a great mea- 
sure supported by it, the face will remain 
above water quite free for breathing, will 
rise an inch higher every inspiration, and 
sink as much every expiration but never so 
low as that the water may come over the 
mouth. 7 . If therefore a person, unac- 
quainted with swimming, and falling acci- 
dentally into the water, could have pre- 
sence of mind sufficient to avoid struggling 
