commonly large, black and diftended, as if fuffocated with blood, the membranes are fometimes ruptured, or they give way in the act of handling the liver. In the firft form, or where black vomiting has taken place, the gall bladder is more or lefs full of bile, often black and thick like tar or molaffes; the gall ducts are enlarged, and the bile is traced into the duodenum, tinging, with its footy colour, the contents of the stomach and intestines.

Spleen. The fpleen is fometimes diftended, ready to burft,of the membranes are actually ruptured; sometimes it is more flaccid, or like a bag of grumous blood.

Bladder of urine. The bladder is often finall and contracted, the fides of it denfe and firm, as if long in a state of constriction: it feldom contains urine, or it contains it only in fmall quantity: on the internal furface are often found bloody fpots, or clots of blood, entangled in the mucous membrane, circular and infulated, like the impreffion of the paint of a bloody finger on a pale furface.' P. 208.

Dr. Jackfon next proceeds to examine the characteristics of thefe two kinds of fever; that proceeding from the vegeto-animal fource, and that arifing from the living fomes of contagion. The appearances of thefe difcafes are nearly the fame, yet it is neceffary to diftinguish them.

In forming an opinion of the existence or non-existence of contagion, it will be neceflary, on all occafions, to bear in mind, that as the conclufion is a matter of much importance in fociety, it muft not be admitted, so as to be acted upon, without the most rigid examination, and the concurrence of many corroborating teftimonies. If various perfons, brought into hofpitals on account of accidents, become affected, in a certain courfe of time, with a fever not connected with their conditions, little doubt will remain that a contagion exifts, or that the fever originates from that fource; if the medical officers, nurfes and attendants become generally affected with the fever prevailing in thofe hofpitals, while a fimilar disease does not appear in neighbouring places, or only as traced to this fource, the conclufion of contagion may be fafely admitted; if clothes, bedding, even the perfons of men, from this infected fource, be removed to a diftant place, a difeafe arifing in this place, and extending itfelf to others, may be justly concluded as proceeding from contagion. Under the above circumftances the existence of contagion may be confidered as pofitive; under the following it is prefumptive, but not certain. If the form of fever, in a country where the character of the endemic is ftrongly marked, be irregular, fluctuating, not exactly obferving the periods of tertian, fimple, or compound, there are grounds to fufpect a caufe of contagion. This was particularly the cafe on the continent in the campaign 1794. The scene of that campaign was laid in a country where intermitting fever is the reigning difcafe, yet genuine intermitting fever ap

peared very rarely, in fuch part of the British army as fell within the obfervation of the author. The disease was fluctuating in its form;-a febrile period of three, or of five days, was followed by a remiffion of uncertain duration,-followed in its turn, by a renewal of febrile motions, ceafing and recurring at intervals,-fometimes for a confiderable length of time. The opinion of the existence of contagion, though not pofitive, will be ftrongly prefumptive, where a certain form of difeafe, fever, flux, or ulcers of the legs, appears in a fociety or ifolated clafs of people, but does not extend without the circle, unlefs from immediate communication. This was the cafe on the continent and in Ireland; medical officers fuffered,military officers, living under the fame general atmosphere, but little connected with the fubjects specified, were ftrangers to ficknefs, When fever prevails epidemically in a town, portion of a town, or diftrict of country, and when nurses, physicians, and attendants on the fick, or even occafional visitors in the districts, become affected with fimilar difeafe, the exiftence of contagion is believed to be established; but this, in fact, is by no means the cafe; for the cause of difeafe generally diffused in the atmosphere of the district, infects thofe who enter its circle without the neceffity of communication with diseased bodies.' P. 216.

To this is added a want of power to propagate fever at a diftance from its fource; and for this reafon, prior to our having read the volume before us, we obferved that the propagation of the yellow fever was not to be feared, unless with it we could import the autumnal conftitutions of the Pennsylvanians. Our author thinks with us refpecting the nature of this formidable fcourge of the United States, and fuppofes it to be the ufual endemic of the country, the common autumnal remittent. This opinion he fupports with many fatisfactory arguments and well-felected facts.

The prognofis is judiciously detailed, and the changes on the days, ufually ftyled critical, ably fupported. Dr. Jackson adds one obfervation, we believe new in the doctrine of infection, viz. that, previous to the fever actually forming, the feptenary period is obfervable; for after receiving infection, though naufea and great inconvenience be for a time felt, no fever appears till the feventh, and fometimes not till the fourteenth day. There fcems, in his opinion, fome change going on in the fluids, before the caufe affumes fuch a power as to be capable of producing the violent effects we have fo often occasion to lament.

The proximate caufe of fever has never yet been afcertained. Our author fcarcely adds to our knowledge; yet he approaches the problem with fo much judgement, that we feem to perceive it in a clearer light.

The human body is formed to be acted upon by external caufes; life is fupported by the application of appropriate ones--it

is endangered by the opposite: the product of faulty combinations of matters,-animal and vegetable, and the fecretions from deranged s action of the living fyftem, feem to poffefs an irritating quality,—a quality, in confequence of which, when in a certain ftate, or when at a certain point of fitnefs, a train of unnatural motions are excited, disturbing, interrupting, or in a manner fufpending the alter nate and uniforin action and reft of the irritable and moving parts of the body, but not difturbing the action of every part, or of every feries of parts, in the fame proportion. When the chief force of the caufe is exerted upon parts of locomotion, tremors, fiartings, and various agitations prevail; when upon the heart and arteries, the motions become irritated, and the current of circulation is difturbed; when upon the veins and colourlefs veffels, parts lefs capable of expreffing action, the motions feem torpid and languid, the circulation is flow, and the current finally stagnates; when locally on organs or parts of the body, the appearances are more complex. Sore legs, inflamed eyes, diarrhoea, and peripneumony are frequent forms of the local action of fever. When thefe are repressed, by a new action excited in the part, general fever, or other local affections frequently arife. The caufe which dire&s this action of fever to organs or feries of parts deferves notice; it seems to be no other than the condition of irritability in parts,-in other words, than the diminished power of refifting caufes which disturb the ordinary and healthy operations of the fyftem,-in many cafes accidental, or arifing from customs and habit. In this manner, and in confequence of this accumulated irritability, from preceding habits of action, the locomotive powers, the heart and arteries are principally acted upon by the caufe of fever, among the labouring and active claffes of men, the veins and colourless veffels, among the fedentary and indolent, the alimentary canal and its connections, among the pampered and luxurious. In the first case, action appears to be increased, and the fever in confequence is named inflammatory; in the fecond, there is little active effort, the ufual train of movemept is difturbed or impeded, and the fever is denominated flow, nervous or putrid; in the third, the whole parts of the organ are involved, and the mode of action is more complex, but the form of fever, refulting from it, is ufually denominated bilious.

Under thofe circumstances, caufes, which alter this figure of locally difeafed action, give rife to commotion in the general fyftem or in a series of parts, till fuch time as another difeafed action is produced in a remote part, or upon an excretory organ. The changes effected on this action, by accident or artificial means, are often rapid; and commonly effected through channels of communication not very obvious to the fenfes: The manner of the whole is indeed obfcure; and it is not pretended that the operation is explained, by what is here faid. It however appears, from the molt general view of things, that the febrile caufe is a caufe of irritation, disturbing, but not increasing in a natural manner, the action of the moving fibre, -on the contrary interrupting, impeding, and as

it were fufpending the operation effential to health and life; by which means, the expreffion of its effects principally confifts in debility and impaired energy.' P. 251.

- Dr. Jackfon, in this explanation, comes very near what we have often faid, that fever confifts in a change of balance, a difturbed equilibrium, probably both in the nervous and circulatory fyftems. This we think arifes from a debilitating caufe; for debility, with difturbed arrangement, conftitutes the whole of fever, fo far as it can be judged of by obvious fymptoms; nor does our author's idea of that irritation, which does not increafe the action of the moving fibre,' greatly militate against the idea.

The eleventh chapter, on the cure of fever, we think a very valuable one; but we need not analyfe the whole; it will be fufficient to speak of fome of the more leading principles. In the early ftages, the ufe of James's powder, joined with calomel, is fpoken of with refpect. Free air is of courfe recommended, and accident feems to have fuggefted the utility of joining to free air, exercife in a spring cart. We well know the advantages of exercife in open air, yet journeys of fatigue we have withed to avoid; for common fevers, not apparently dangerous, have been more frequently fatal, fo far as our obfervation has extended, when, from neceffity, the patient has been removed from a diftance in the earlier ftages. We mention this not to oppofe our author's remark, but to prevent it from being too haftily adopted without due confideration in this climate.

In the cure of the endemic fever of America, and the Weft Indies, the propriety of bleeding has been much canvaffed. Our author is a friend to the practice, on what we think judicious grounds. When the fever is forming, his great object is, by a bold decifive conduct, to change forcibly the exifting fate of things. The advice is judicious, though the language is not exactly what we fhould have chofen. A large bleeding is one of his decifive meafures, and this is followed by James's powder, calomel, and affufion of cold water, as well as moving the patient in a carriage through the pure air, theltered from the fun. In the fecond ftage, that of oppreffion, bleeding is ftill recommended, and it was in this state we attempted to find fome clue to fupport and explain Dr. Rufh's facts, in our review of his work on the bilious fever of Philadelphia. The bleeding, in this ftate, muft not be flight, but continued till a change in the exifling fiate of the circulation be affected.' This our readers may recollect was the fituation of Dr. Dover's patient, and the rule of his conduct. Even in the third ftage, bleeding and ftimulating purgatives are, in Dr. Jackfon's opinion, highly ufeful. The more

minute and particular management of the remedies cannot be abridged with advantage. We are furprifed that our author had not refted fomewhat on the authority of Dr. Mofeley,, who has recommended a fimilar practice; but Dr. Jackson is very fparing in general of drawing from any fource but his own. In the account of different methods of cure, the con duct of the French phyficians, ufually fo much extolled, is fpoken of and explained with great candour. On the whole, he does not coníider their fuccefs as greater. The progrefs of fever is, he thinks, lefs rapid under their management: recovery is alfo more flow, but relapfe is lefs frequent. The method of cure by calomel does not meet our author's approbation.

The confequences of fever are very accurately detailed, and the local action of a febrile caufe, either as thrown on the inteftines producing diarrhoea and dyfentery, or on the skin occafioning eruptions or ulcers, carefully examined. The fubjects of the two laft chapters are prevention' and 'convalefcence,' which need not detain us.

The fecond part contains an Explanation of the Principles of Military Difcipline, Military Economy, and a Scheme of Medical Arrangement for Armies.' The obfervations, in this part, are bold, original, and we fear unfafhionable. The author's object is to abandon the ftiff fyftem of German tactics; to familiarife the foldier to labour, to active exertions, to a dependence on his own powers;-above all, to infpire his mind with a generous patriotifm, with a love of virtue, and a fenfe of true religion, which, in the moment of active fervice, will give an energy and fpirit which can never be fuggefted by the fyftem at prefent adopted, of firaight lines, of flow and formal motions.

On the whole, we think this work truly original, and that it difplays much ufeful information; and we can recommend the author as a man of ability, judgement, and obfervation.

An Hijorical Defcription of ancient and modern Rome; also of the Works of Art, particularly in Architecture, Sculpture, und Painting. To which are added, a Tour through the Cities and Towns in the Environs of that Metropolis, and an Account of the Antiquities found at Gabia. Carefully collated with the best Authorities, by J. Salmon, Antiquary, late of Rome. Embellished with beautiful Engravings from original Drawings. 2 Vols. 8vo. 11. 10s. Boards. Taylor. 1800.

NUMEROUS, in a variety of languages, are the defcriptions of Rome, once the political, and afterwards the religious, tyrant of the European world. Yet we do not recollect having met with any minúte and fatisfactory detail in our own