clonic contraction, before you feel that your task is done or the process of parturition is completed.

I will not detain you longer upon this point, than to make a mere mention of the evils which may result from non-performance of this stage. Hæmorrhage may at once occur; the utero-placental vessels, not closed by contracting fibres, may be more or less filled by coagula and extension, migration or absorption of these may create thrombosis, embolism, septicemia, or phlebitis; clots or pieces of placenta remaining may cause uterine angeio-leucitis, endometritis, or absorption of septic matter by wounds in the vagina.

The possibility of these evils should make the obstetrician careful to see that complete, firm and persistent closure is effected by manual compression, after the passage of the child until the bandage is applied; by the invariable administration of ergot and systematically fostering and not depressing the patient's strength, especially for the week or ten days immediately following delivery.

Contagion. That there is a peculiar ærial influence, a "pestilence which walketh in darkness," which produces erysipelas, hospital gangrene and similar affections, no one can dispute. As this influence exerts its baneful effect upon the stump left after amputation, so may it do so on the bared uterine wall and produce similar results, which, in turn, go on to the creation of peritonitis.

Much may unquestionably be done to avoid this result, by removal of the woman, expecting confinement, from the locality in which the serial poison had demonstrated its presence, scattering the patients of lying-in hospitals, and preventing contact with persons, who in their clothing, might convey it to the lying-in room.

Besides this poison, we know that there are others which excite the kind of inflammation to which I have

alluded. Among these are decaying animal matters conveyed to the patient's body upon the hands of the physician or nurse, or in the air of the room. To avoid these, the room of the sick woman should be kept scrupulously clean; napkins saturated with lochial discharge and all alvine or vesical excretions should be at once removed.

The obstetrician should never expose his patient to the danger resulting from vaginal "touch" by him, if he have been recently engaged in making a post-mortem examination, dressing a wound affected by erysipelas or hospital gangrene, or indeed, doing anything which could subject the genital organs to a septic influence. Whether the hands have been employed in such a way as to have been contaminated by putrescent material or not, they should never, unless absolute necessity require it should be avoided, be introduced into the uterus for removal of the placenta.. Introduction of the hand into the vagina is a matter of no moment, except in so far as it gives pain. Introduction of the hand into the uterus is always attended by the danger of endometritis, and should never be resorted to, except for good cause.

Foul Air.-I told you that nurses are commonly impressed with the idea that post-partum diseases are often the results of exposure to cold. To avoid such exposure they often shut up every crevice by which fresh, pure air can enter the chamber. In consequence, the atmosphere becomes loaded with carbonic acid gas, the exhalations of the bodies of those in the room, one of whom is a young infant, from whom alvine evacuations are constantly occurring, and worse than all, with decaying animal matter, which is steadily pouring from the vagina of the mother. The air of the lying-in chamber should be as free from poisonous elements as its floors and walls; the temperature should be maintained at 70°; and all drafts or currents of cold air should be avoided.

When the dangers attending a process, which is commonly, even by professional men, unreflectingly regarded as one almost entirely free from risk, are thus analyzed, and presented a very illogical argument, a species of "reductio ad absurdum" is often resorted to in order to meet the statements advanced. Such an one as the following I have heard proposed in reference to the subject of which I have just treated. "If all these dangers are real, how is it that all women do not die in confinement?" My answers to the question are these: 3,000 women do die annually from this cause in England and Wales alone, and probably 1,000,000 die in one generation from it in the civilized world. No one doubts the risk of being injured in a hard fought battle. The influences which may cause death are numerous, yet all the men who enter one are not killed or wounded, nor are one-fifth nor even one-tenth injured in the slightest degree.

He who would avoid a danger must fully appreciate its character before he can begin to strive against it, and he who most intimately understands its nature will most successfully contend with it.

ART. II. THE PHYSIOLOGY OF THE CEREBRAL CIRCULATION, CEREBRO-SPINAL FLUID AND CEREBRAL MOVEMENTS. BY STANFORD E. CHAILLÉ, M.D., Professor of Physiology, etc., Medical Department University of Louisiana.

Few subjects teach better than the history of the cerebral circulation, how readily false conclusions can be drawn from well-established physical laws; and with what forcible ingenuity, and for how long a time these false conclusions can be maintained in opposition to the most familiar, but adverse facts. It was long taught that, since the cranial, unlike other cavities, is an air-tight incompressible box, filled with incompressible contents;

and, since such a box must always contain the same amount; must alwas be full, or failing this, produce that physical impossibility in the animal economy, a vacuum; therefore, that the amount of blood, one of the cranial contents, must remain always the same and could not, by any physical possibility, vary.

A half-dozen autopsies ought to have sufficed to have proved that there was in this, therefore, faulty logic somewhere. But they did not and the true facts were rejected until the error in the false conclusion was pointed out. It was at last found out that there are three important cranial contents; that, besides brain and blood, there was another fluid, and that this cerebro-spinal fluid played so important a part in the cerebral circulation that physiologists were enabled to amend their theory and make it accord with the facts. These still teach that the total amount of contents in an air-tight box, as the skull, cannot vary; but that the relative proportions of the different contents can and do constantly vary. One may be augmented, provided another is correspondingly diminished; two even may be augmented, provided the third is as much minus, as the sum of the two others is plus. This is exactly what occurs in the brain, as may be daily seen in the dead house. There, in ordinary cases, the brain is found little altered in size, but the quantities of blood and fluid are seen to be constantly present in varying amounts, which are in inverse ratio to each other. The more blood the less fluid, and vice versa. So that the presence of an unusually large quantity of normal fluid in the ventricles and around the brain simply indicates anæmia of the brain, whilst an unusually small quantity is equally indicative of hyperæmia. If the brain be diminished in size, as in alcoholic atrophy, there be an unusual quantity of both blood and fluid; so too, if the cranial cavity be enlarged, as in hydrocephalus, the brain

maintaining its normal size, then too, both blood and fluid, may be in excess. But, in these two conditions only, can there be an excess of both. It is also worthy of remembrance, that causes operating after death may modify the respective quantities of blood and cerebro-spinal fluid found present within the skull; and indicate conditions different from those existing during the life of the subject examined. All admit these facts, but let it not be supposed that this varying quantity of cerebro-spinal fluid in the brain is only a pathological condition. In the cases mentioned, it is but an excess of a physiological function which is in constant and momentary action. So that this history of the cerebral circulation first gave a definite idea of the physiology of the cerebro-spinal fluid, and is a proper introduction to its consideration, and to that of the cerebral movements, in whose production it plays a very important part.

The cerebro-spinal is a serous fluid, which, however, in its normal condition lacks one of the principal characteristics of other serosities. It does not coagulate on the application of heat; owing to the absence of albumen, or to the very minute quantity it contains. Robin teaches that it is the only normal serosity which is constantly present, and that it is the most abundant of all. Its quantity is very variable, and it is readily absorbed and reproduced; depending on the degree of pressure to which it is subjected. Its average quantity is estimated at about two ounces, but in cases of cerebral atrophy as much as twelve ounces have been collected; and, in a ease of fractured skull with laceration of the membranes, Bernard states, that owing to its rapid reproduction when lost, over two pints flowed out in twenty-four hours. In this case the fluid flowed in expiration, thus indicating that it was subjected then to augmented pressure. Magendie, led by erroneous interpretation of his experi