once. Whenever, says Bazin, "Tinea tonsurans has already, for some time, reached its papulo-pustular period, depilation must be performed, even if we be sure that the parasite no longer exists; it is in these cases that the disease yields as if by enchantment to our treatment; a single depilation may suffice; aud on this account it is that the cure of mentagra may be said to be easy in proportion to its chronicity." The same author remarks, that much time is often lost in vain attempts to subdue the inflammation and tumefaction of the skin in mentagra before resorting to avulsion of the hairs, under the impression that the inflammatory action would be increased by the operation; but the real agent of irritation is the hairs, which act the part of a foreign body and stimulate the inflammatory process; and the best method of dissipating it, would be to remove the foreign body, which is the cause of all the mischief. After avulsion our remedies perform wonders.

Treatment of Alopecia Areata.-The treatment of area is to be conducted on the same principle as that of the other forms of tineanamely, the application of phyticides and depilation. Bazin remarks that the puny hairs which are found on the bald patches of area are difficult to remove on account of their weakness, and that repeated depilations are therefore necessary; he also reminds us of the necessity of carrying the depilation to a slit distance beyond the limits of the patch into the region of the sound hair.

Treatment of Phytodermatous Furfura.-The treatment of these affections, including chloasma, is, according to Bazin, extremely simple: no internal treatment is called for; the parasitic fungi are situated superficially in the epidermis, and the phyticidic remedies already enumerated are all the treatment required; they may be used in the form of lotion, forcible friction, or baths, according to their situation or extent. The treatment commonly pursued by this author is to apply the bichloride of mercury lotion and use sulphurous baths, but he gives the preference to baths containing the hydrargyri bichloridum*. Epitheliophyta.-Carrying out his views of the parasiticidic operation of the bichloride of mercury, Bazin recommends it as a wash for the mouth in aptha, to destroy the Oidium albicans, in preference to the biborate of soda. And upon the same principle he favours the use of the pyroligneous oil of juniper in chronic ulcers.

OPSERVATIONS.-The chief point of novelty in the treatment of Tinea, as advocated by Bazin, is depilation; but this recommendation is far from being new; it was practised by Plumbe, by Rayer; it is the basis of the treatment of the Mahons, and the principle of the notorious "calotte," so long, and we fear at present, in use in France. But the objects of the treatment are different; Bazin removes the hairs because they are the harbour of a parasitic vegetable fungus, which developes seeds, and consequently, as long as it remains, keeps up and extends the disease. Plumbe, Rayer, the Mahons, and the promoters

The strength of the mercurial bath ranges from one drachm to three, and may be carried as high as one ounce. It will be recollected that this salt of mercury is soluble in water only to a limited extent. The bichloride lotion varies from one-eighth of a grain to one grain to the ounce.

65-XXXIII.

15

of the calotte, because the hairs are supposed to act the part of foreign bodies and irritants to the inflamed skin. "In old standing cases of favus," says Rayer, "every method of treatment into which the avulsion or removal of the hair does not enter as an element, is incomplete, and unworthy of being entitled curative."

The depilation recommended by Plumbe differed from that of Bazin in being partial; the same objection may be made to that of the Mahons, which operates only upon the loosened hairs; while the calotte is an instrument of the grossest barbarity, tearing out alike sound and diseased hairs, and in a manner the most painful that could be contrived. Bazin's method is painful enough, and to many persons would be insupportable, but every care is taken to make it as gentle as possible; the skin is rendered less sensitive by the previous application of the juniper tar, and the hairs are withdrawn artistically, no doubt in the direction of the set of the shaft, with moderate and steady traction, and to a limited extent at each repetition of the operation. With reference to the rest of the treatment, it differs in nothing from that which has been in common use in this country for a number of years-namely, washings with soft soap, combing and brushing the hair, and the use of mercurial pomatums, of which the nitric oxide and ammonio-chloride of mercury are examples, and tar and sulphur ointments, which in public institutions are highly popular.

With the exception of mentagra, we believe depilation to be wholly unnecessary in these diseases; we believe that they may be successfully cured, as they have been heretofore, without depilation. We never find any overwhelming difficulties in the treatment of these complaints; they are tedious, but not remarkably so when properly managed, and we decidedly declare against depilation. Depilation may be, and no doubt is, a great boon in the treatment of tinea in France, but it is worthless in England, where more care is bestowed upon the constitutional treatment of cutaneous diseases.

And what, it may be asked, is the treatment on which we rely for the cure of these diseases? We will state it briefly ::-We remove crusts and furfuræ by thorough washing with the juniper tar or petroleum soap, or with a liniment consisting of equal parts of soft-soap, juniper tar, and alcohol. We repeat the washing daily with tepid or cold water, with the double object of cleansing the diseased parts and giving a moderate stimulus to the skin of the head; we comb the head well, brush it if not too sensitive, and night and morning we rub into the entire scalp, but most into the patches, an ointment consisting of one part of the nitric oxide of mercury ointment, diluted with three parts of fresh lard. In milder cases we wash the head less frequently, but we continue the combing and brushing and anointing steadily. A failure of cure is an event that we cannot anticipate and rarely see.

But we do something more: we administer mild tonics; we prescribe a generous diet; we treat symptoms; and, in a case of favus-a disease of the scrofulous diathesis-we have recourse to cod liver oil and the iodide of iron. Moreover, in certain cases, where no indications of general debility exist, where the nutritive functions seem

principally at fault, we administer arsenic, with the most brilliant success. Favus and Trichosis capitis are diseases of children and adolescents, and this method of treatment answers admirably with them. In Trichosis corporis (Lichen annulatus solitarius et serpiginosus) we have for many years been in the habit of prescribing a lotion, or ointment, of the bichloride of mercury; and in chloasma, or pityriasis versicolor, we prescribe ablutions with the juniper-tar soap, sponging with a spirituous solution of the bichloride of mercury in almond emulsion; or frictions at night with one of the diluted mercurial ointments already mentioned, and ablution in the morning with the junipertar soap. In Trichosis barbæ, or mentagra, we are ready to admit the value and importance of avulsion of the hairs; not, however, as a means of removing a supposed parasite, nor of an irritant foreign body, but as a healthful stimulant to a part in a state of chronic and irritable inflammation.

And this brings us to the question of the use of depilation: that it disposes to the cure of the local disease there can be no doubt. We cannot disbelieve the statements of Bazin that he succeeds in curing these diseases through the agency of depilation; but we do and must disbelieve that the removal of the fungus is the proper explanation of the cure. We see in depilation a stimulant, and a valuable stimulant —a stimulant that we ourselves commonly use when we seek to make a black hair grow up in place of one that is white-a treatment that for this purpose we have been in the habit of using for years, and with remarkable success; so that we have been led to regard avulsion as one of our best, indeed our only reliable remedy for producing deep stimulation of the cutaneous tissues, for setting up a new action in the papillæ of the hair; as the only remedy, in fact, by which we can reach successfully the fundus of the hair-follicle. And this, in our belief, is the "methodus medendi" of depilation and avulsion in the phytodermic diseases. It sets up a new action, a healthful inflammatory process in place of a morbid inflammatory process-a process whose natural course is to end in resolution, instead of one whose nature is perpetuity. For morbid cell-genesis it establishes healthy and plastic inflammation and sometimes healthy suppuration, when, as Bazin declares, the fungus is starved or drowned. Even Bazin has recourse to avulsion as a stimulant in old cases of mentagra, wherein the hair acts the part of a foreign body, of a thorn, in the skin, and so keeps up irritation.

Hardy makes the following very practical observation in reference to the treatment of the Phytodermata :-"It will not be sufficient to destroy the parasitic fungi only; we must modify the soil so as to render it inapt to the reception of new germs, and unfavourable to their nutrition. We must give tone to the constitution by means of tonics and bitters, prescribe good food and closer attention to cleanliness, and cut the hair short to admit of the action of the air upon the scalp."

PART FOURTH.

Chronicle of Medical Science

(CHIEFLY FOREIGN AND CONTEMPORARY).

HALF-YEARLY REPORT ON PHYSIOLOGY.
By HENRY POWER, F.R.C.S., M.B. Lond.
Lecturer on Physiology at the Westminster Hospital.

I. CIRCULATION AND RESPIRATION.

1. J. SACHS: An Inquiry into the Seat of the Formation of Carbonic Acid in the Animal Body. (Reichert and Dubois-Reymond's Archiv, 1863, pp. 345.) 2. SCZELKOW: On the Interchange of Gases which takes place in the different Organs of the Body. (Sitzungsberichte der Wien Akad., Band xlv. 1862, p. 171.)

3. M. EDENHUIZEN: Essay on the Physiology of the Skin. (Henle and Pfeuffer, Zeitschrift, iii. Reihe, Band xvii. p. 35-105.)

1. Sachs observes that three opinions may be held upon the seat of the formation of carbonic acid in the animal body: 1. That it is formed in the tissues, from whence it passes into the blood; 2. That it is exclusively formed in the blood; and 3. That it is generated in both places. At first sight the objection made by Ludwig against the formation of carbonic acid in the tissues appears to be a strong one-viz., that if this be the case, the pressure or tension of the carbonic acid in the tissues should be greater than it is in the blood; but direct observations prove the contrary. Thus Schumowsky has shown that even the muscular tissue does not contain more than about 14.4 per cent. of carbonic acid; and as regards the fluids of the body, Schöffer states the amount of carbonic acid in the urine to be 44 per cent., whilst its proportion in the milk varies, according to Setschenow, from 5:01 to 6-72 per cent. In all these instances, therefore, it is present in a proportion far below that in which it is contained in the blood. But the force of the objection vanishes if it be remembered that a large portion of the carbonic acid naturally present in the blood is in combination with the phosphate of soda, and that only a small part is really free. In order to ascertain whether carbonic acid is generated in the blood, the method pursued by Sachs was to divide a freshly drawn portion of blood into two parts-to examine the gases in one immediately, and to set the other aside for some hours before obtaining the gases from it. He draws the following conclusions from six experiments, made with great care:-1. The gases contained in the blood after its removal from the body, at ordinary temperatures undergo marked changes in their relative proportions, the oxygen gradually disappearing, and carbonic acid taking its place; the quantity of carbonic acid generated being, however, always greater than the volume of oxygen which has disappeared. 2. The quantity of carbonic acid that is chemically combined in the blood increases with the interval at which it is examined after removal from the body; and he agrees with Schöffer and Sczelkow in consider

ing the quantity of chemically combined carbonic acid to be always greater in venous than in arterial blood. 3. Though the number of experiments was too small to found positive statements upon, it appears that after forty-eight hours the quantity of oxygen remaining in the blood is reduced to a mere trace, and after that period (for some time at least) the gases suffer no further change. 4. He was unable to draw any definite conclusions in reference to alterations in the proportion of nitrogen. 5. The presence of fibrin is a necessary condition for the formation of carbonic acid in the blood, but the exact role which it plays cannot as yet be definitely stated. From these results he believes that he is justified in the general conclusion, that carbonic acid is constantly being generated in the blood at the expense of the oxygen present in it, and that consequently carbonic acid is not formed exclusively in the tissues.

2. In Sczelkow's experiments three kinds of blood were compared:-1. That obtained from the carotid artery. 2. That obtained from the femoral vein when the muscles of the leg were quiescent. 3. That obtained from the same vein when the muscles of the leg were tetanized. In the following table the first is indicated by A, the second by V R, and the third by V B:

It thus appears that 100 vol. of venous blood returning from muscles at rest contains on the average 6.71 vol. more carbonic acid than is contained in 100 vol. of arterial blood, whilst 100 vol. of venous blood returning from contracting muscles contain 10.79 vol. more CO2 than 100 vol. of arterial blood. On the contrary, the venous blood of quiescent muscles contains 9 per cent. less oxygen than arterial, whilst in the venous blood of contracting muscle the quantity of oxygen may not exceed 1 or 2 per cent., arterial blood containing from 12 to 173 per cent. by volume of that gas.

3. Edenhuizen has investigated anew the effects of suppressing the action of the skin in various animals by covering them with different kinds of varnish. The experiments were made upon sheep and rabbits, a dog, a weasel, a mouse, a pigeon, and two frogs. On completely covering the animal, the duration of life was usually longer in proportion to its size, providing it was strong and healthy. If more than from one-eighth to one-sixth of the body were covered in rabbits, they quickly died. Immediately after the operation, a temporary increase in the frequency of the respiratory acts, of the pulsations of the heart, and of the temperature of the body was usually noticed; but in a short time these all fell below the normal standard-at first rapidly, and subsequently more slowly, though uninterruptedly, till death supervened. Other symptoms which appeared when a considerable portion of the skin was varnished were, restlessness, strong rigors, dyspnea, paralysis, tonic and clonic convulsions, languor, and the secretion of a considerable quantity of albuminous urine. On keeping a