preliminary according to Dr. Fergusson. These points, however, require further investigation, and we must for the present be content to admit that malaria is, as a general rule, more abundantly evolved where the three conditions stated by Dr. Wood exist in the greatest abundance.

At p. 143 Dr. Wood remarks, "** the increase of disease which often follows the commencement of cultivation in a newly settled country is in consequence of the turning up of the soil loaded with vegetable remains ;" and "that though the first steps of civilization in a wild malarious region, often rather increases the production of the poisonous agent, yet, with the progress of cultivation the country becomes even more healthy than it was originally, in consequence partly of draining and embankments, and partly, perhaps, of the productive growth to which the vegetable decay is made tributary." The second part of these remarks is of vast importance to us of the Southern and South-Western malarious regions, and the question is, is it true? have our lands become more salubrious with increasing clearings and cultivation ? So far as our own State is concerned, we have the strongest evidences to the contrary. From the first settlement of this State the sickly period has gradually been becoming longer. When our lands were first opened and cultivated our ancestors resided upon their plantations the whole year, with the exception, probably, of the months of August and September. At present, wo to him who remains so late as the 15th of July-indeed, as a general rule, the 15th of May is the time at which our planters remove. Indeed, some of the most severe cases of fever we have ever known, occurred as early as the middle of May. Prudence, therefore, warns the planter to fly early to the healthy pine ridges, which fortunately, are numerous in our State, or to resort to the city, until the return of frost and cold weather again render it safe for him to return to his home. So far, then, from the healthiness of the low country of SouthCarolina having improved with increased cultivation, it has steadily deteriorated. It is true that our lands are as yet imperfectly drained, that fresh clearings are yearly exposed to the action of the sun, and that our rice plantations must necessarily be kept more or less wet during the whole of the summer months; but fever is contracted almost as surely on the oldest cotton plantations as on any others.

That trees act as protectives against malaria we cannot doubt. Dr. Fergusson, in the work already quoted, gives the strongest proofs of this. Were further proof wanted we could adduce the extensive experience of the inhabitants of our low country, where villages, pre

viously healthy, have been rendered insalubrious by the encroachment of clearings upon them. Another strong instance has also come to our knowledge: the residence of the proprietor of a large farm, in one of our middle districts, was situated on an eminence at some distance from the cultivated bottom lands, skirting a creek which flowed through the farm. Between the house and the cultivated low-grounds there was a belt of woods. The family enjoyed perfect immunity from fever until this wood was cut down, immediately after which remittent and intermittent fevers made their appearance among them. We know too little of the nature of malaria to speculate on the manner in which trees act to neutralize its influence.

Dr. Cartwright, of Natchez, (quoted by Dr. Wood, p. 145,) ascribes extraordinary anti-miasmatic properties to the Jussieua grandiflora, an aquatic plant which grows abundantly in certain ponds. To this he attributes the healthiness of certain portions of Louisiana, in the stagnant waters of which the plant grows abundantly. But the exemp. tion from fevers in those localities must depend on other circumstances, for the Jussieua grandiflora grows abundantly "around Charleston for the space of ten miles, in situations where it is well known that fevers of a malarious origin continually prevail."

"Though," says Dr. Wood, "malarious diseases may rage around a city, and even invade the outskirts, where dwellings are comparatively few, yet they are unable to penetrate into the interior; and indivi duals who never leave the thickly built parts almost always escape," p. 146. This fact is strongly exemplified in our city. In the thickly built parts, remittent and intermittent fevers are scarcely known, and in the outskirts in proportion as the buildings extend and cover more ground, those parts, which before were extremely liable to malarious fevers, become healthy, and their place is, in regard to health, taken by the more recently constructed habitations.

Our author next inquires into the nature of Malaria; but after pass ing in review the different theories which have been advanced on the subject, he, like most other candid observers, concludes that none are satisfactory, and that we must be content with knowing it only by its effects. Among other theories mentioned, is that of Sir James Mur. ray, who ascribes to disturbances in the electro-galvanic currents about us, and through us, the production of the diseases termed malarious, He goes even so far, as to say, that houses constructed in a peculiar

*See Medico-Botanical Catalogue, July number of this Journal for 1847, p. 406,

note.

manner with floors of asphaltum or other non-conducting substance, two or three lightning rods communicating with metallic tubes sunk in the ground on each side of the house, containing water, and connected by wires, which pass under the house-are comparatively healthy in malarious regions. These ideas, speculative as they may seem, have recently been in substance maintained by M. Pallas, Chief Physician in Algeria. He has for some time devoted great attention to this subject, and has, he thinks, modified many diseases by isolating the patients, by putting glass feet to their beds, &c. He contends that marshes are in their composition and effects on the system analogous to the galvanic pile; that experiment shows that electricity exercises a special action on the nervous system; that marsh fever is primarily nervous; that most of the neuroses are occasioned by an exaggerated influence of the general electricity; that intermittent fevers have the same origin, i. e., from the electric emanations from marshes.*

We do not pretend to think that these ideas are established, nor do we believe malaria to consist solely in a disturbance in the electric currents about us; but as the subject is so important and so obscure, we lay these opinions before our readers, and call the attention of those residing in malarious regions to the subject, inviting them to endeavour, by experiment and observation, to elucidate this obscure part of etiology.

If there be truth in Sir J. Murray's theory, may not the tall pine tree, with its numerous tufts of pointed leaves high in the air, and its roots struck into the soil, act in the same manner as his artificial conductors of electricity, and thus aid, in some measure (for we believe trees to act in other modes in neutralizing malarious influence) in rendering the land which they shade safe for the residence of man?

Malaria, in Dr. Wood's opinion, enters the circulation principally by absorption into the circulation through the lungs; it may also be absorbed through the skin, or swallowed with the saliva. The peculiar diseases produced by miasmata, as our readers know full well, are remittent and intermittent fevers. Besides these, a long list of maladies are ascribed to its influence; but the fevers referred to, with their secondary effects, are its peculiar products.

Dr. W. regards the inhabitants of malarious regions as enjoying comparative immunity from their fevers. This, however, is true only in degree, the inhabitants of these regions having fever quite as frequently, although of a milder form, than strangers.

Epidemic Influence. Dr. Wood seems disposed to adopt the ani*Bulletin de l'Acad. de Med. June 30, 1847, p. 742.

VOL. II.NO. V.

47

malcular theory to account for the prevalence of epidemics, regarding the "analogy as strong between the movements of certain epidemics, and those which might be supposed to be the result of animal impulses and caprices, in migrating swarms of insects." But, he admits. that this, like all other explanations, is purely hypothetical. This article, though short, is very interesting and instructive.

The leading

article con

Contagion. "Any product of a peculiar disease, which is capable of producing the same disease in another person, and of thus propagating itself, and the complaint of which it is at once the cause, and effect through any number of unprotected individuals." This definition strikes us as one of the most complete we have seen. phenomena of contagion are concisely stated, and the cludes with a few remarks on the theories of contagion. Until we understand thoroughly, in what the matter of contagion consists, we cannot speculate with any hope of forming rational theories on the subject. The chemical theory of Liebig, which regards the matter of contagion as of the nature of a ferment; which, meeting in the system with some peculiar matter, on which it acts, and "which, through the fermentation, excited by the contagious cause, is itself converted into contagion and eliminated; so, that on any future occasion, though the poison may be absorbed, it will find no material to act on, and will therefore be harmless;" we have always regarded as one of the wildest speculations of the great German Chemist. For, in the first place, it would suppose that the composition of the blood was fixed and permanent, instead of being, as it is, ever changing, subject to constant waste, and constantly being renewed; or, it would suppose certain principles to be secreted or formed in the blood but once during the life of each individual; And secondly, the idea of so many distinct fermentescible principles existing in the blood, under these circumstances, is to us altogether inconceivable, for it is necessary that one should exist for each contagious disease, one for each contagious exanthem, another distinct one for hooping cough, another still for typhus, &c.

Under the head of predispositions, we observe nothing worthy of special remark. In our next number we will take up the work again, and will offer a few remarks on some of the other general principles laid down in it.

From what has been said, the reader will perceive that we think highly of Dr. Wood's Practice. What we have found to censure we have pointed out, and where we have differed in opinion with the author, we have not hesitated to express our difference. We can, with

out hesitation, recommend the work to the profession as one of the most carefully prepared and best digested on the subject which we possess. If we have any fault to find with it, it is that the author has not relied sufficiently on his own experience, and has not spoken sufficiently on his own authority; we would not have had him, however, do so dogmatically.

The publishers deserve credit for the handsome and substantial manner in which the work is published.

"Scire po.

III. Medical Botany; or Descriptions of the more important Plants used in Medicine, with their History, Properties, and Mode of Administration. By R. EGLESFELD GRIFFITH, M.D., Member of the Am. Philos. Soc. of the Acad. Nat. Sci., Phila., &c. testates herbarum usumque medendi." Æneid XII. 396. With upwards of three hundred illustrations. Philadelphia: Lea & Blanchard. 1847.

It will be noticed that the work before us, is neither an American Medical Botany, nor strictly and exclusively a Medical Botany. It is in fact somewhat more, the eighty introductory pages being devoted to collateral subjects having relation, either directly or indirectly, to the main design of the book. Works of this class are exceedingly rare, forming one of the chief items of our desiderata. It is remarked that there is a paucity even among the Germans on this subject, so that undertakings of the kind must present more than ordinary difficulties, and those of a peculiar nature; they are obvious, and will be referred to in the course of the remarks which follow.

The anatomy of plants, in reference to vegetable tissue and its intimate structure, vesicles, ducts and cells, first engage our attention. The organs of nutrition, form and function of leaves, re-production, physiology of fecundation and propagation, description of parts, including those of ferns, &c., are severally treated of. Vegetable physiology took its rise under Grew and Malphigi, who first paved the way for succeeding discoveries by Brisseau, Mirbel,* Dutrochet, and still later by Ehrenberg, who have from close microscopical inspec

* Traite d'Anatomie et de Physiologie Vegetales. Paris. 1802.