exert upon the large tide of blood flowing through it, the presumption is natural that it must hold important relations with other parts of the vital machinery. Overfeeding, indigestion, and exposure to vicissitudes of temperature, are capable of inducing functional and organic derangements in this large gland. Redundance and deficiency of bile are observable in different forms of dyspepsia; and the exciting cause of inflammation and abscess, especially in hot climates, is the arrest of perspiration, from exposure of the body without the necessary clothing during sleep to the night air, sometimes to a

sea-breeze.

Says Mr. McIlwain, "Where the liver has been once diseased, or when it retains any chronic form of disorder, no persons know better how soon it is excited into active disorder than those who labor under the malady." IIe recollects the case of severe jaundice in a woman who was doing exceedingly well, but who, without any apparent cause, had on two occasions a sudden relapse of her symptoms. She had been forbidden to eat animal food; and on the second relapse she inquired whether it was possible that a small piece of ham, actually not more than a moderate mouthful, could have caused the recurrence of her symptoms? On her being told, somewhat doubtingly, that very small portions of offensive matter did sometimes. produce considerable disturbance in deranged conditions of the stomach, she said, "I think it must be so; for on the first occasion I had eaten precisely the same thing.""

1

By keeping in view the sympathetic relations of different parts, we may often find valuable suggestions in regard to the treatment of disease. The following interesting case from Mr. McIlwain is in point:

1 Med. and Surg. one Inductive Science. London, 1838. McIlwain.

"Sarah Jones, aged forty-two, 13 Water Court, Islington, a patient in the Finsbury Dispensary, applied for relief on account of the following symptoms: She has lost her voice, not being able to speak otherwise than in a whisper. She attributed the loss of her voice to getting wet in the feet almost five months since, her bowels being at that time costive, which is her general habit. Her catamenia have ceased rather more than two months; her bowels are costive; her tongue yellowish-white; her gums are much elevated, and highly vascular; her urine scanty, but clear. Her skin acts every night in an unusual manner; she describes herself as being bathed in a most profuse perspiration. Mr. Leigh and myself agreed to try first what stimulating the kidney would do, since, she being able to go about her business with such important functions imperfectly executed or actually suspended, it seemed probable that the profuse action of the skin was the source of immunity from more serious ailments. Taking, therefore, the hint thus afforded, we proposed to make the kidney participate more than it appeared to do in the excreting function. In order to keep the reasoning as close as we could, we simply gave her a diuretic - the nitrate of potash.

In three days, she came and surprised us not a little, in the first place, by speaking in her natural voice. She said that the medicine had produced more water, and natural in appearance; but that her bowels had also acted very freely; and, on the occasion of the second action, the catamenia had returned. The profuse night perspirations, she said, she had 'quite lost.' We kept her under our care about a week longer, during which time she remained quite well."

CHAPTER VIII.

MAN BY NATURE A VEGETABLE-EATER -VEGETARIANISM.

§ I. MAN BY NATURE A VEGETABLE-EATER.

AMONG the larger animals, the organs which are employed in preparing the food for nutrition show a distinct relation to those articles designed by nature for them to feed upon. Animals are herbivorous, carnivorous, and omnivorous, or vegetable-eaters, flesh-eaters, and eaters both of flesh and vegetables.

Of vegetable-eaters there are two varieties: fruit-eaters and grass-eaters. The first feed upon pulpy fruits, esculent roots, nuts, and seeds; while the others derive a great part of their nourishment from the grasses, leaves, and twigs of vegetables. The teeth of the fruit-eaters are formed upon a particular model. The lip teeth or incisor teeth are chisel-shaped. Behind these are the cuspid or canine teeth, each terminating in a single point, generally obtuse. Next in order are the bicuspid or premolars, each terminating in two blunt points or cusps or tubercles. The remaining teeth, sometimes called cheek teeth, molars, or large grinders, are four-sided, with rounded anglestheir broad terminal surfaces presenting four or five cusps or tubercles. On each side of the median line, in each jaw, there are two incisors, the upper central ones broader than the lateral,— eight in all; one cuspid or canine, four

in all; two bicuspids or premolars, eight; three cheek teeth, or molars, twelve-thirty-two. All are covered with enamel.

These differently

Fig. 24.

shaped teeth are arranged in broad
arches in the jaws. The lip teeth in
the upper jaw shut down anterior to
those in the lower; while the pre-
molars and the molars, or small and
large grinders, meet and close upon
each other when the mouth is shut.

If we refer to the highest order of
apes, as the orang-outang, the chim-.
panzee, and the gorilla,-all of which
in the natural state are frugivorous,
we find their teeth answering to

Fig. 25.

the foregoing description. The chisel-shaped lip teeth
are well fitted for dividing into convenient morsels the
materials naturally fed upon; the canine teeth, espe-
cially in the male, projecting somewhat
beyond the level of the others, are obvi-
ously weapons of defence - having prob-
ably nothing to do with the food, unless,
perhaps, in some instances, to aid in
removing the rind or shell from certain
nutrient articles; the long and sharp
canine teeth of the gibbon, or long-
armed ape, make him a respectable
enemy under an attack, notwithstanding
the comparative want of strength in his arms; the pre-
molars and molars are evidently made for crushing and
grinding the food-this process being greatly facilitated by

In early youth the orang has a high and rounded head, but as he grows older its form changes, and at full age his skull is flat and not capacious.

the motion of the under jaw, which is so articulated with the skull as to admit of motion from side to side, and to some extent, also, in the antero-posterior direction.

Fig. 26.

The grass-eaters have teeth adapted to the comminution of their food; the grinders in the lower jaw shutting against those in the upper, while the lateral or side motion of the lower jaw exists, as with the fruit-eaters.

The large carnivorous quadrupeds have teeth of a very different type.

Their lip teeth, or incisors, are six in SKULL OF THE FULLeach jaw; those in the upper and lower

—

GROWN CHIMPANZEE.

exactly meet each other when the mouth is shut. In the cat family, as the cat, lion, tiger, leopard, - they are arranged nearly in a straight line from one canine to the other. In the dog family, as the dog, wolf, fox, they are somewhat arched, with an anterior convexity. These would seem to be designed for gnawing off small fragments of flesh adherent to bones too hard and strong to be crushed down by the larger teeth.

Next are the canines, one in each side of each jaw, strongly implanted, long and pointed, and employed in seizing and lacerating the animals they feed upon. Back of these are the premolars, different in shape and number in the different flesh-eaters. Next are the trenchant or cutting teeth, generally two in each side of each jaw. From a thick base, where they emerge from the jaw, they are scarfed on the inner and outer side to a blunt edge, which is deeply notched. These teeth in the lower jaw shut within those of the upper, forming a kind of shears, adapted to cutting off successive pieces of flesh; the notches in the trenchant edges prevent the bit of flesh