the organic nervous retina; more oxygen, as well as blood, is admitted into the arteries, and more heat, as well as electricity, is evolved. The electricity decomposes the serum of the blood, the hydrogen of the latter unites with the oxygen, and some of the salts of the blood secreted by the gland forms saliva, which passes off by the excretory ducts of the gland.

A good illustration of the connection between the animal and organic nervous systems is afforded by watching the appearance of a bashful person, when charged with some ludi

crous act.

The brain communicates with the superior central ganglion, and the latter communicates, through the brain and facial nerve, with the organic nerves surrounding the transverse facial artery, (it will be recollected branches of the facial nerve accompany this artery;) the result is, that the capillary arteries at once become dilated, and are injected with arterial blood, giving a crimson color to the face, at the same time that the temperature of the cheek is increased, in consequence of the large quantity of oxygen supplied to the organic glands.

When a person is afflicted with grief, the brain, the chief ganglion of the animal nervous system, communes with the superior central ganglion, the chief ganglion of the organic nervous system. The latter communes, through the brain and lachrymal branch of the ophthalmic division of the fifth nerve, (animal,) with the organic nerves surrounding the capillary arteries, and entering into the formation of the organic glands, in the lachrymal gland.

Explanation.

When the distribution of the nerve is recollected, as well as that it inosculates with the organic nerves of the parts to which the branches are distributed, there cannot be much trouble in accounting for the suffused condition or redness of the eyes, the capillary arteries being dilated so as to admit blood where. none was visible previously. The mode in which the tears are

secreted by the organic glands can be explained by recollecting the capillary arteries are dilated, carry more blood, as well as oxygen, and consequently, that on the union of the oxygen with the glands, more heat is the result, as well as a greater amount of electricity; that the electricity decomposes the serum of the blood in its passage through the gland, and that the hydrogen unites with the oxygen, as well as some of the salts of blood secreted by the gland, forms tears, which pass off by the excretory ducts of the gland.

Milk-Draught.

A familiar example of the connection between the animal and organic nervous systems is presented in what is commonly called the milk-draught. As soon as the mother sees her child after a short absence, her breasts will instantly become filled with milk. Here the explanation consists in recollecting that the brain communes with the superior central ganglion; the latter, through the spinal cord, with the inferior cervical ganglion, which communicates through the thoracic branches of the brachial plexus with the organic nerves surrounding the branches of the mammary artery; dilatation of the arteries takes place; more blood enters the arteries, consequently more oxygen. The organic glands commence their operations, and secrete the constituents of the milk; the electricity evolved on the union of the oxygen with the glands decomposes the serum of the blood; the hydrogen of the latter unites with the constituents of the milk, combined with oxygen, and forms milk.

Mental Emotions.

Mental emotions of an amatory character demonstrate the connection between the animal and organic nervous systems.

The excitement, being of a pleasurable description, is communicated from the cerebrum, the great animal nervous ganglion, to the superior central ganglion, the great chief of the organic ganglionic system; the latter communes through the brain and facial nerves which inosculate with the capillary retina of nerves surrounding the coronary arteries of the lip; the result is, the arteries become dilated, and contain more blood; hence the pouting of the lips that ensues.

Again, further communication is had through the thoracic branches of the brachial plexus which inosculate with the organic nerves surrounding the mammary arteries distributed to the nipple; the arteries become dilated and injected with blood; hence the erection of the nipples is the consequence.

Again, through the pudic nerve, whose branches inosculate with the organic branches of nerves surrounding the pudic artery, and distributed to the clitoris; hence dilatation, injection, and erection of the clitoris, and, in the male subject, erection of the penis.

Vital Action-Depression of the Organic Nervous System. Why a person who is told dreadful intelligence gets deadly pale, is accounted for by recollecting that the brain communes with the superior central ganglion, and the latter through the brain and filaments of the facial nerve, which inosculate with the organic nerves surrounding the transverse facial arteries, rendering the nerves powerless, causing contraction of the capillaries; the circulation becomes feeble and the countenance pallid.

When a person, whilst at breakfast or dinner, is told a disgusting story, or happens to see a disgusting object, his stomach rejects its contents. The brain communes with the superior central ganglion; the latter through the branches of the par vagi, which inosculate with the organic nerves of the stomach surrounding the arteries; the nerves at once contract, followed by contraction of the capillary arteries, as well as by contraction of the muscular fibres of the stomach, to which the arteries are distributed. Contraction of the whole stomach is the result, with the discharge of its contents.

"Sea-Sickness."

When a person is standing on the deck of a ship which is tossed about by waves in a storm, the various objects are impinged on the retina so rapidly that the mind has not time to take cognizance of them, and becomes confused and disturbed; the confusion and disturbance are propagated to the superior

central ganglion, and through the branches of the par vagi to the organic nerves surrounding the arteries of the stomach, with which the branches of the par vagi inosculate; the confusion and disturbance of the mind are thus communicated to them, causing contraction of the nerves surrounding the capillary arteries. Contraction of the arteries must be consequent on the contraction of the nerves, and contraction of the muscular fibres of the stomach must be consequent on the contraction of the arteries. Contraction of the stomach, rejection of its contents, and dreadful nausea, are the results of the disturbance and confusion propagated by the animal to the organic nervous system.

Depression, Excitation, Irritation of the Organic Nervous System, produced by External Agents.

Having demonstrated that the organic nervous system could be depressed or excited by its connection with the animal nervous system, I will now demonstrate that the organic nervous system can be depressed, excited, and stimulated by external agents.

Pneumonia.

When a person is exposed to rain and cold for the greater part of the day, he is liable to be seized with great depression, coldness of the surface, and shivering; the organic nervous system is greatly depressed, and its functions impeded. After a certain interval, the surface grows warm and hot, the countenance becomes flushed, and the pulse strong and full. Reaction has taken place, and the organic nervous system is in a state of high excitation. After a short time, heavy pain will be felt in the side, accompanied by oppressed respiration. The excitation of the organic nervous system is now followed by irritation, which accounts for the pain in the side.

Phlegmon.

Constant exposure to wet and fatigue is very often followed by an abscess, or what is usually called a phlegmon. The patient, after experiencing chilliness for some time, has his atten

tion attracted to a certain part of the body or extremities, which has become hot and swollen. After the lapse of some time, severe pain, of a throbbing character, is felt in the part. The chilliness denotes the depressed state of the organic nerves; the heat affords evidence that the organic nerves surrounding the arteries have recovered from the shock; that dilatation of the capillary arteries has taken place; that an increased quantity of blood, and consequently, an increased quantity of oxygen, flows into the capillaries, and consequently that the temperature of the part is increased, on account of the larger amount of oxygen supplied to the organic glands. The pain demonstrates that the organic nerves are suffering from irritation, and are about throwing off the offending matter by the secretion of lymph and pus. The phlegmon, it will be perceived, affords a good example of the depression, excitation, and irritation of the organic nervous system; besides, gives an excellent illustration of the phenomena of what is generally or universally called inflammation.

"Rubor et tumor cum calore et dolore."

Excitation and Irritation of the Organic Nerves on the External Parts of the Body.

"Chancre."

The application of syphilitic poison to the organic glands of the prepuce or glans penis is not followed by any change in the part for some days. Itching and redness of the part will first attract attention; heat and pain immediately follow. A conical elevation (papilla) surmounted with a vesicle, to be replaced with pus, is lastly observed.

The poison takes some time to imbue the organic glands with the virus; consequently, during the incubation of the poison, no change is observable; but as soon as the poison has taken effect, excitation of the nerves takes place, followed by dilatation of the arteries and a larger flow of arterial blood into the arteries, and consequently an increase of the temperature of the part, by the additional supply of oxygen furnished to the organic glands. The pain is caused by the irritation consequent on the continued excitation of the nerves, and gives