the mode of its exhibition and the circumstances of the individual be taken into consideration. I have tried its effects upon the lower classes of animals; on a few individuals only of those of vermes and insecta; and, so far as the characters of the respective tissues in the highest and in nearly the lowest of the scale of animated nature have a common resemblance, so far the effects assimilate.

1st. I consider that this, like the other essential oils, acts primarily as a stimulant upon the nerves of the texture to which it may be applied, in whatever dose it may be given. This is sufficiently obvious, and has, indeed, been generally allowed.

2dly. When taken internally in a moderate quantity, it excites very slightly the action of the heart immediately after ingestion, by nervous communication between the different ganglia and plexi.

The immediate, but very moderate, action of the heart fol lowing its exhibition in a very large dose upon an empty stomach, proves this.

3dly. That the vertigo and intoxicated feeling, (as it is erroneously called,) with diminution of the mental and animal powers, together with the concentrated energy felt in the abdominal viscera, prove that the vital influence of the system and force of the circulation become principally exerted in the viscera in the immediate vicinity of, and in those chiefly supplied with, the ganglial order of nerves, while the other two orders of the nervous system experienced a proportional deficiency; as was shown by the languid circulation and diminished functions of organs depending upon the cerebral and spinal orders of nerves for their supply of nervous influence; and, consequently, that the vertigo, and what has been called the intoxication of the patient, after its ingestion, have arisen from the diminished energy of circulation in the brain. This was proved by my own feelings at the moment; by the shrunk features, pale countenance, and the state of the circulation in the brain, as evinced by the pulsation of the carotids, not in my own case alone, but also in several whom I have narrowly observed while thus affected by this substance.

4thly. It is rapidly absorbed into the circulation, unchanged by the fluids of the digestive canal; and it appears to undergo no change during the circulation of the blood through the various viscera, and is ultimately thrown off by means of the Jungs, kidneys, and the secreting and exhalent surfaces; and, during its circulation in the capillary and terminal vessels, it excites their tonicity and action, without inducing any considerable degree of subsequent relaxation.

5thly. When present in the blood in small quantity, it imparts a tonic action to the arterial and capillary vessels, as well

as to the heart. But, if it continue to be absorbed into the cir culating mass faster than it can be eliminated from it by the different organs destined for that purpose, so that an undue accumulation takes place, as in the instance just detailed, it exhausts or overpowers the irritability of the heart in such a manner as to render this organ incapable of propelling the blood with the requisite energy to the extreme vessels.

6thly. That a large quantity of this substance, when circulating in the mass of fluids, does not always affect the kidneys so severely as has been generally believed.

7thly. In addition to, or perhaps resulting from, its action upon the nervous energy of the part, it acts also upon the insensible contractility or tone of the texture to which it is applied.

(a.) Thus it increases the tone and rigidity of muscular fibres.

(b.) When applied to the mucous and cellular textures, it gives them the appearance of increased density of structure.

(c.) It also diminishes the secretions from the mucous follicles of the digestive tube, by constringing the orifices of the excreting ducts and exhalant vessels; and hence one reason for its uncertainty as a purgative.

(d.) It combines with the mucus covering the interior of the intestines, forming with it a gelatinous substance; as I have observed in several instances wherein it has been exhibited as

an enema..

(e.) If applied to the mucous membrane when deprived of its fine cuticular covering, it gives this tissue a corrugated and more blanched appearance; apparently from constringing its texture and capillary vessels, so as to diminish their calibre and prevent them from admitting the red particles of the blood. It may also, in some degree, combine with this tissue after the manner of tannin, even while it still retains its vitality.

8thly. A large dose of this medicine does not always affect the peristaltic motion of the intestines in such a manner as to cause them to evacuate their contents, unless it be given along with some other purgative.

(a.) This may arise from the continued and tonic action it excites in the muscular fibres of the intestines, and which, when induced in the colon, may so act upon the longitudinal bands of fibres collected on the surface of that viscus, in exciting their tonic contraction simultaneously with the like action in its cir cular fibres, as to throw it into valviform folds, and by these means to obstruct, in the completest manner, the passage of the feces along its canal.

(b.) When its purgative effect is produced, it acts entirely by exciting the fibres of the intestinal tube into contraction; while, No. 269.

at the same time, it restrains the secretions from the mucous surface: hence its uncertainty as a purgative when given alone. (c.) Its cathartic effects are more certain, the greater the quantity of feculent matter existing in the prima via at the time of its ingestion. This I have proved, by giving it soon after the bowels have been evacuated by a previous aperient. It has then produced tenesmus, and afterwards even bloody urine, if not followed by an additional purgative. Its more steady action as a cathartic in these circumstances may be explained, by its stimulant effects being chiefly confined to the part with which it comes in contact, which portion, undergoing contraction, pushes the accumulated matters through a successive and more yielding portion of the tube, before a similar degree of contraction can be imparted to it, owing to the intervening, and in some degree consistent, feces preventing the actual contact of this substance in the inferior portion of the canal.

9thly. Its actions on the economy of the higher animals, and its agency as a remedy in disease, are referrible,-1st, to its effects upon the parts to which it is primarily applied, and which, as I have already noticed, may vary according to the constitution and texture of the part; 2d, to its effects by means of nervous communication and continuity of tissue, which are very confined; 3d, according to its presence in the circulating fluids, and the quantity of it existing in the blood within a given period; and 4th, to its effects as they may result from the simultaneous actions of the three preceding,-namely, the effects arising from its local influence and resulting sympathies, and from its presence in the circulating mass of fluid.

10thly. This substance appears to act in a nearly similar manner upon animals of the classes insecta and vermes, (from the few trials I have made ;) and according to the proportion existing between the nervous system of the animal and the dose. But the effect is greatly modified by the texture to which it is applied, and according as it may come in immediate contact with their respiratory organs.

(a.) When applied to these organs in sufficient quantity, it acts by producing a mechanical impediment to changes induced by the air.

(b.) It also constringes the texture and orifices of their respiratory organs.

(c.) In addition to its effects upon the nervous system and respiratory organs of those animals, it produces an astringent effect upon their soft and gelatinous tissues, apparently from combining in part with its texture, and preventing the evolu tion of its functions.

Having shown its effects upon the animal economy, according as my opportunities have afforded me the imperfect knowledge,

I would have pursued the subject, by making some observations respecting its employment as a remedy of no mean efficacy in various diseases; but, as I might be led to a tedious length, I shall defer the fulfilment of this intention until the following Number of the Journal.

Walworth Terrace; May 1821.

An Account of a new Mode of preserving an equable and salutary Temperature of the Air of Rooms for Consumptive Patients. By THOMAS ANDREW KNIGHT, Esq. F.R.S. President of the Horticultural Society, &c. &c.

I

TRANSMIT the following communication to the London Medical and Physical Journal, under an impression that it points out a better method of creating an artificial climate for patients with tender lungs, than any generally known; and I write with the hope of averting from other parents, and other families, a calamity which I believe it has been the means of averting from me and my family.

The patient, who was the subject of the mode of treatment which I proceed to describe, had been perfectly healthy, though her appearance was delicate, from her birth, till she married, and had one child. Her appearance then, in her nineteenth year, became consumptive; and, within a few weeks afterwards, a sudden and very considerable discharge of blood, apparently from her lungs, but too plainly pointed out the nature of her complaint. It was proposed immediately to convey her to a southern climate; but, owing to events which I need not detail, this was not done. She passed the first winter in rooms which were kept warm and of as equal temperature as circumstances would permit; but there was a necessity for several blisters and the application of leeches. In the succeeding summer, her health and strength appeared somewhat to improve; but at the end of the following winter she was so much emaciated and reduced by a long-continued discharge of blood from her lungs, and the effects of her feverish state, that I thought all hope of her recovery past; and I should have been much less unhappy respecting her if she had been at peace in her grave. I had, however, the consolation to find that her physician, Dr. Wilson Philip, (whose important and singular physiological discoveries have, of course, made his name familiar to every medical man,) did not despond. He pronounced decisively that, if she remained another winter in the climate of England, her death was inevitable; but he expressed his hope and belief that, if she could be placed in a situation where she could have the benefit, during eighteen successive months, of a climate as favourable as the best part of an English summer, she would recover

her health and strength, and be subsequently able to bear an English winter, though her lungs could never wholly regain their former power. Measures were consequently taken to convey her abroad; but I found in her a settled conviction that she should go never to return, and that her remaining strength was wholly unequal to the exertion necessary.

Under these circumstances, I thought only of the best means of giving her, as far as practicable, the advantages of a warm and temperate climate at home; and, having been much in the habit of making such climates for plants, I looked forward with some hope, though with trembling anxiety, to the result. I stated to Dr. Philip my confidence that I could give to the air of the rooms in which I proposed that she should pass the winter, such a degree of humidity (she breathed most freely in somewhat damp weather,) as should be found best to agree with her, and any temperature, with little variation, which he should think likely to be most beneficial; and the following plan was adopted, with (under existing circumstances,) his most unqualified approbation. A flue of sufficient power, and surrounded by an air-chamber of just sufficient dimensions to permit a person to go round the flue to ascertain that no smoke escaped into the air-chamber, was constructed wholly of brickwork; space being prepared to receive garden-pots, to be filled with wetted sand, to give to the heated air the requisite degree of humidity; and, from the top of this air-chamber, pipes of tin, cased with wood, were made to convey a warm current of air, to rise through different parts of the floor of every room into which she should have occasion to enter. She was thus given the benefit of a warm temperature,-that of sixty degrees, with little variation,-as proposed by Dr. Philip, with a constant and rapid change of air. A summer temperature of eighteen months was thus given, and the result has succeeded my most sanguine hopes. The patient has perfectly recovered ber health and strength, and she suffers no further inconvenience from her past illness than inability to walk briskly up bill, or to sustain any continued bodily exertion, without being soon out

of breath.

Particular attention was paid to prevent the temperature of the air of the bed-room of the patient from becoming too low at an early hour of the morning in winter; that being the time at which, I have had reason to believe, patients with tender lungs usually suffer most in cold weather. It is probable that, in the case above stated, the patient was, to a great extent, be. nefitted by judicious medical treatment in every other respect: but upon this subject I do not feel qualified to speak.

London; June 13, 1821.