blood for heat is greater than that of venous, that there is no difference of temperature between the two ventricles of the heart, and, in fact, that the heat of all parts is nearly the same.

They are more agreeable to, and indeed they even support, the hypothesis of Dr. Black, that animal heat is produced in the lungs, and distributed over the whole system by means of the arterial blood.

Neither are they inconsistent with that hypothesis which considers the production of animal heat as dependent on the energy of the nervous system, and arising from all the vital actions constantly occurring.

Besides the results of the preceding experiments, many arguments may be advanced in opposition to Dr. Crawford's hypothesis.

As we never perceive a difference of capacity in bodies without a difference of form or composition; and as very slight differences of the former result only from great changes of the latter, it might be expected a priori, as no difference, excepting that of colour, has been detected between venous and arterial blood, that their specific caloric would be very similar. From analogy also, it might have been expected, that the capacity of arterial blood for heat would be much less than that of water, as water appears to exceed almost every other fluid, and as the capacity appears to diminish as the inflammability of compounds increases. But the strongest arguments against this hypothesis are to be derived from the recent experiments of Mr. Brodie, and those of MM. Delaroche and Berard.

Dr. Black's hypothesis appears to me far more satisfactory than Dr. Crawford's, and capable of explaining a much greater number of phenomena; but there are objections even to this hypothesis, which must be removed before it can with propriety be received.

The last hypothesis, which I mentioned, that which refers animal heat to vital action, has many facts in its support, and especially the results of Mr. Brodie's curious and interesting experiments; and the results of my inquiry, as I have already observed, are not incompatible with it. It may be said, that the viscera of the thorax and abdomen are of highest temperature, because these parts are, as it were, the elaboratories of life; and that the heat of the arterial blood, and of the parts best supplied

with this fluid, is greatest, because they lie deepest and abound most in the principle of life or vital action. This explanation was suggested to me by my brother Sir H. Davy. There are some facts which I have observed agreeable to it, but not more so than to the hypothesis of Dr. Black. I have found the stomach of the ox, the pyloric compartment, of a higher temperature than the left ventricle itself: thus, when the latter immediately after death was 103, the former full of food was 104.5. I have also found the temperature of young animals, in whom all the vital actions are most energetic, higher than that of animals arrived at maturity. I may mention here, in illustration of this statement, a few observations made on infants, as I am not acquainted with any yet published. In one instance I found the heat under the axilla of a child just born 98.5; after twelve hours 99, and after three days, the same; during the whole of which time it appeared in perfect health. On five other children of the same age, similar observations were made. In two instances of weak infants, the temperature, one hour after birth, was found not to exceed 96, which is two degrees below the standard heat of man in a state of health; but their respiration was still languid, and the next day the heat of the axilla had risen in one to 98.5, and in the other to 99.*

To conclude: As, in each hypothesis examined, difficulties are found to exist from facts or the results of experiments of an unbending nature, we must at present either suspend theory altogether and search for experimenta crucis, or adopt that hypothesis which is conformable to the greater number of facts. The first measure is certainly most philosophical; but to the latter we are naturally most inclined; and if I were questioned which view is preferable, I should make no hesitation in selecting Dr. Black's, which to me appears both most simple and most satisfactory.

The opinion of Haller, I am well aware, is contrary to these results, as is expressed in the following paragraph: “Viri feminis calidiores duriori nempe sunt fabrica, contra pueri aliquanto minus calent quam adulti homines, ut modo natus puer vix calorem conservet, nisi sollicite et copiose vestibus textus."-Elem. Phys. ii. p. 297. As this great physiologist seems to have drawn his inference merely from the circumstances mentioned, it can have little force, except from the authority of the author; to which may be opposed an equal authority, not less than that of Hippocrates himself: he says, in his fourteenth aphorism, "Qui crescunt plurimum habent calidi innati: senibus autem paucus calor."

On the Cultivation of Senna.

[From the Raleigh Star.]

MESSRS. EDITORS,

I UNDERSTAND that Senna has lately advanced in price three hundred per cent. It is a most valuable article of medicine, and perhaps its increased price is not to be regretted, as it will make us acquainted with our own resources, and compel us to improve them.

Some years since, the Medical Society of North Carolina (a valuable institution, which I am sorry to perceive is inactive and languishes, if it be not extinct) offered a premium for the production of the largest quantity of Senna, exceeding 40 pounds, raised by one person in one year. I accordingly sowed about a quarter of an acre, and obtained between fifty and sixty pounds of Senna, which physicians have said was much superior to the coast of Barbary Senna, and equal to the best which comes from the Levant.

Since Senna bears a high price, and is not easily obtainable at any price, I have hoped, that every person who keeps a garden, will not in future subject their means of health to the will of a foreign despot; and in this hope I am induced to send you for publication the information necessary to be known by those who are desirous of cultivating this valuable article.

It is a delicate plant, sensible to cold, rains and drought: The seeds should be committed to the earth about the first of May; the ground should be mellowed and the seeds planted in rows, covered an inch deep and four inches asunder.-The rows should be a foot or two apart, so as to admit of being worked, and the only tillage necessary is to keep it clear of weeds and to earth it moderately. If the season is dry or the soil thirsty, it would be benefited by an occasional watering. The plant in good soils grows to two-thirds of the height of indigo, but spreads more. The leaves (the valuable part) grow on long stems issuing from the trunk and branches.

Besides a drought, the Senna is exposed to another formidable enemy. When in bloom it is visited by a yellow butterfly which deposits its eggs upon the leaves in vast abundance.VOL. VI. No. 22.

2 B

These eggs in a few days become worms, which destroy the leaves. I know no means of preventing the visitation of these troublesome flies, nor any expeditious mode of staying the advances of these eggs to the animal state. Sprinkling ashes over the shrubs has been recommended by some, and has suggested itself to me, as a probable means of being useful in both cases, but I have never tried it. The only mean which I have attempted was to brush off the eggs with a wing where I have detected them. This is a work of some labour. The eggs are small and white, and will not be observed without minute inspection. The later in the season the plant is in coming to maturity the more liable it is to the depredations of this butterfly progeny. Hence the propriety of bringing it forward as early as the season and its tender nature will permit.

The Senna is to be gathered once or twice a week as the plant is going on to maturity. When the lower leaves have gained their full size and begin to change their colour a little, pluck off a few courses of the lower stems: wilt them two or three hours in the sun, then spread and dry them in the shade, pick out the stems, put up the leaves in bags suspended in an airy dry situation.

The seeds are contained in pods which grow at the extremity of the stalk and its branches. As they ripen they become black and fall off. Gathering the leaves does not at all injure the production of seed.

A light rich soil is best. If sandy, it is liable to suffer from drought.

Senna is now two dollars a pound in Petersburg. The product of a quarter of an acre would be worth a hundred dollars. The value of the labour is so inconsiderable as to make a very small deduction from this amount. It would be profitable to cultivate for sale and export. But every family ought to cultivate it for private use. It is a most valuable cathartic, perfectly safe, mild in its operation, and a most powerful evacuant of bile, and as far as my observation extends, much superior to jalap and calomel, and certainly much preferable to those drastic drugs. It renders the operation more mild to add a few coriander or fennel seeds to it when a decoction is to be prepared.

Wake county, April 3, 1813.

JOHN WHITAKER.

SELECTED REVIEWS.

A Practical Explanation of Cancer in the Female Breast, with the Method of Cure, and Cases of Illustration. Вy JoнN RODMAN, M. D. One of the Surgeons and Medical Superintendants of the Dispensary and House of Recovery of Paisley. 8vo. pp. 240. London, 1815.

[From the London New Medical and Physical Journal, for May, 1815.]

In taking a survey of the whole catalogue of "ills which flesh is heir to," there is not one which strikes such horror into the human mind as that which is the subject of the volume before us. If hydrophobia be terrific in its appearance, and almost invariably fatal in its result, still the victim of its fury is soon released from corporeal sufferings by the welcome hand of death. If pulmonary consumption be almost as certain in its melancholy termination as hydrophobia, while its career is often long protracted, yet the patient's sufferings are comparatively trifling, and hope gilds every prospect till the last curtain falls! Not so in Cancer,there agonizing pain of body keeps the sympathising mind perpetually on the rack, and hope, "which comes to all," but rarely illumines the gloomy prospect of the unhappy patient. The ravages too of this dreadful disease, though accompanied with such torment, are cruelly slow. A fœtid and horrid-looking ulcer gradually destroys every thing in its way, till the bones themselves are corroded, and the patient sinks from the general and local irritation, or from the repeated hæmorrhages occasioned by the destruction of those arteries that lie within the range of the malady!

No part of the human frame, in either sex, is so frequently the seat of Cancer, and also of those tumours which have been mistaken for incipient cancers, or schirrhi, as the female breast; and it is the disease, as it affects this particular organ, which our author has selected for his Essay. After so many authors had written on this disease, without explaining its nature or offering any thing like a successful method of treatment, we confess that we opened the work with a gloomy presentiment that this would but swell the catalogue, without in