DISEASE is brought on by the action of the exciting cauſe, after the body is rendered capable of receiving the contagion by the action of the prediſpoſing cauſe. The yellow fever being a contagious diſeaſe, it muſt undoubtedly depend upon the action of a poiſon either generated or introduced into the body. This matter, or poiſon, is generally acknowledged to be exhaled from animal and vegetable ſubſtances in a ſtate of putrefaction: but, as there is a great contrariety of opinion upon this ſubject, I ſhall purpoſely paſs it over, referring the reader to the works of LAVOISIER and others.— There are alſo many different opinions as to the mode in which this contagion acts upon the body in producing the diſeaſe. Some have ſuppoſed that it enters the ſyſtem by the ſtomach—ſome that it enters by the lungs—and others, that the body receives it by the pores of the ſkin. All theſe opinions have their advocates; but by whichever paſſage it is communicated to the ſyſtem, whether by the ſtomach, the lungs, or the pores of the ſkin, it is certain, that, in common with the matter of ſmall-pox, meaſles, lues venerea, the venom of the rattle-ſnake, &c. it produces a violent irritation throughout the whole ſyſtem. Its firſt operation I conſider to be upon the nervous ſyſtem: hence the violent pains of the head, back, and extremities of the body—hence the ſickneſs of ſtomach and vomiting— hence the ſenſation of cold and conſtriction upon the ſecreting and excreting veſſels. Such an irritation upon the nervous ſyſtem, with an interruption to the ſecretions and excretions, are neceſſarily followed with a quickened circulation. The irritating matter of itſelf is ſufficient to produce this effect; but the ſuppreſſion of perſpiration, the confined ſtate of the bowels, and eſpecially the retention of bile of an uncommonly acrid quality, muſt alſo unqueſtionably have a ſhare in adding to this irritation and increaſed action.

HAVING ſtated the ſymptoms and cauſes of the diſeaſe, we are next to conſider the indications of cure, which appear to be,

Firſt, To prevent the further operation of the poiſon producing the diſeaſe.

Secondly, to procure a ſolution of the inflammatory ſtage of the fever.

Thirdly, To counteract the putreſcent ſtate of the body, as deſcribed in the ſecond ſtage of the diſeaſe. And,

Laſtly, to reſtore the tone of the ſyſtem when the preceding indications are accompliſhed.

Firſt, To prevent the further operation of the poiſon producing the diſeaſe. To this end it is neceſſary that the patient be removed from the atmoſphere in which he took the diſeaſe, and placed in a ſituation where he may enjoy a pure, free air: all articles capable of conveying the contagion ſhould be immediately removed from the body, ſuch as clothing, &c. in place of which there ſhould be clean dry clothing, bedding, &c.

Secondly, To procure a ſolution of the inflammatory ſtage of the fever. It is neceſſary to moderate the increaſed action of the ſyſtem, and to remove, as far as poſſible, every other ſource of irritation. To evacuate immediately the poiſon from the body, when one introduced, is as impoſſible as to eradicate the matter of ſmall-pox, meaſles, or any other diſeaſe produced by ſpecific contagion. In the treatment of yellow fever, as in that of the ſmall-pox, if the analogy be a juſt one, t 〈…〉 ſneſs of the phyſician appears to be, to moderate the action of the poiſon producing the diſeaſe, and, at the ſame time, to remove every circumſtance which can aggravate its operation upon the body. With a view to diminiſh the increaſed action of the ſyſtem, evacuations of different kinds were employed. Some practitioners had recourſe to blood-letting, followed by purging and ſweating; and others truſted entirely to the two latter. With reſpect to blood-letting, my obſervation has been, that the promiſcuous uſe of the lancet was very injurious and unſucceſsful. In the New-York hoſpital it was frequently employed, but in the majority of caſes the diſeaſe terminated fatally; yet, in ſome few inſtances, where the conſtitution was uncommonly plethoric, and the determination to the head more violent than uſual, I have obſerved good effects follow the loſs of a moderate quantity of blood. But, generally ſpeaking, blood-letting was attended with pernicious conſequences. The ſame has been confirmed by the obſervations of ſeveral of our moſt reſpectable practitioners. The more common and ſucceſsful practice was,

1. To procure a free evacuation from the bowels. The purgative medicines which were employed were many and various. By ſome, calomel and jalap were preſcribed, and, in the beginning of the diſeaſe, with good effect. Others adminiſtered a mixture of rhubarb and magneſia with cinnamon or mint-water. This alſo anſwered well in many caſes, where the ſtomach was irritable, and rejected the former medicines. But the medicine which was the moſt ſucceſsful, and acquired the greateſt reputation, was the Glauber's ſalts, given in warm diluting drinks. The doſe was generally from one to two ounces, diſſolved in a pint of gruel made of Indian meal, and given in divided doſes until it operated freely; the patient at the ſame time drinking freely of gruel or chicken water, to promote its operation. Salts, exhibited in this form, for the moſt part ſat well on the ſtomach: they were expeditious in their operation, and, in many inſtances, poſſeſſed the additional advantage of relaxing the ſkin and inducing perſpiration, eſpecially where the patient drank largely during their operation. But when the ſtomach was ſo much irritated as immediately to reject every thing taken into it, recourſe was then had to glyſters, compoſed of vinegar and water, quickened by the addition of a ſmall quantity of molaſſes: theſe ſcarcely ever failed to produce the intended effect.

2. Having procured copious and free evacuations from the bowels, the next object appeared to be to relax the ſurface of the body, and induce free perſpiration. In ſome inſtances this ſalutary diſcharge came on immediately after the bowels had been emptied, and was readily continued by taking plentifully of warm drinks; but, for the moſt part the febrile ſymptoms continued violent, the ſkin remained hot and dry, the pains ſtill diſtreſſing, and it became neceſſary to have recourſe to more active means to induce ſweating. For this purpoſe many ſudorific medicines were employed. Some practitioners uſed emetics, and others ſmall doſes of James's powders, and the different preparations of antimony. Vomiting, in this diſeaſe, I have generally obſerved to be of dangerous tendency. It may, perhaps, not be amiſs, when the diſeaſe firſt diſcovers itſelf, and is attended with much ſickneſs and vomiting, to empty the ſtomach freely, by means of an infuſion of chamomile flowers: but the exhibition of emetics I conſider to be highly dangerous and improper. I believe I have ſeen ſome caſes in which the death of the patients could be aſcribed to no other cauſe than the inceſſant vomiting brought on by an emetic given in the commencement of the diſeaſe. But the moſt certain and ſucceſsful means were, to waſh the whole ſurface of the body with cold vinegar and water, and immediately after covering the patient with blankets—to adminiſter ſuch medicines as poſſeſs the effect of bringing on ſweating: of theſe the ſpiritus mindereri and ſaline draughts of RIVERIUS ſucceeded well, more eſpecially if the warm drinks were continued, ſuch as the infuſion of ſnake-root, gruel, toaſt water, tamarind water, lemonade, &c. Theſe were much aided by applying to the feet of the patient a warm brick, ſteeped in vinegar and covered in a flannel cloth wet with vinegar or ſpirits: the ſteam, thus emitted and diffuſed through the bed, had a wonderful effect in ſoftening the ſkin and exciting ſweat, eſpecially where the cold waſhing had been previouſly employed.—Some practitioners have preferred the practice of plunging the patient ſeveral times in a cold bath, and violently daſhing the body with cold water. But ſimply waſhing the patient with cloths dipped in cold vinegar and water, was found much preferable to immerſion, both becauſe it more effectually diminiſhed the heat of the ſyſtem, and was leſs fatiguing to the patient. Experiments have proved, that repeatedly wiping and waſhing with water, in the ordinary way in which the operation is performed, diminiſhes the heat ſeven or eight degrees more than ſimple immerſion, or daſhing it over the body with pails.

THE practice of cold bathing in fevers of this type is not a new one, but was very commonly employed at Breſlaw, in Sileſia;See DE HAEN's Ratio Medendi. and of late years has been very ſucceſsfully applied in the Weſt-Indies,Doctor JACKSON on the Diſeaſes of Jamaica. as well as in different parts of Europe, where diſeaſes of this type prevail.

PROFESSOR GREGORY, of Edinburgh, and Doctor CURRIE, an eminent phyſician at Liverpool, have alſo preſcribed it with great advantage in the low typhus fevers of thoſe cities. But its great ſucceſs in the New-York hoſpital, as employed by Doctor SAMUEL BARD, and in the private practice of my brother, have fully convinced me of the propriety of its uſe. It is alſo proper to remark, that where the phyſician was not called to the patient in the firſt ſtage of the diſeaſe, and putrid ſymptoms had appeared, and the patient had become much debilitated, the cold bath was injurious; and from the abuſe of cold bathing, by employing it in the laſt ſtage of the diſeaſe, it has fallen into diſrepute with ſome practitioners. But as the abuſe of a thing is no argument againſt its uſe, I repeat my obſervation, that in the firſt or inflammatory ſtage of the diſeaſe, it was one of the moſt uſeful remedies that was employed. When the cold bath had been thus made uſe of, and immediately after followed by the ſpiritus mindereri or ſaline mixture, with plentiful dilution, it rarely failed to produce ſweating in the courſe of fifteen minutes; and when once induced, it was eaſily continued by the repetition of the ſudorific medicines and drinks, until a ſolution of the fever was obtained. In ſome inſtances where the patient refuſed his drink and medicines, or, from the careleſſneſs of the nurſes, they had not been ſupplied as frequently as was proper, and the perſpiration had been ſuppreſſed, it became neceſſary to repeat the cold bathing, which ſeldom failed to procure a return of the ſweating. By the continuance of this diſcharge an abatement of all the ſymptoms took place: it appeared to operate as a ſpecific in the diſeaſe; the pulſe in a ſhort time became moderate; the heat of the ſkin diminiſhed; the pain in the head and back, before ſo diſtreſſing, was alſo relieved; the ſickneſs of ſtomach and vomiting were removed; and, in the courſe of two or three days from the attack, the patient had little elſe to contend with but mere debility.

Thirdly, In thoſe caſes where the phyſician was not called in the early ſtage of the diſeaſe, where the bowels were not freely emptied, and perſpiration had remained ſuppreſſed, with a continuance of the fever, a more diſtreſſing train of ſymptoms appeared, as deſcribed in the ſecond ſtage of the diſeaſe, and required a different mode of practice: few patients, however, recovered from this ſtage of the diſeaſe.

WHERE the ſtomach was much diſturbed with ſickneſs and vomiting, which was one of the moſt dangerous ſymptoms, the ſaline draught was exhibited in the efferveſcing ſtate; and, in ſome inſtances, yeaſt was employed with advantage, followed with nouriſhing antiſeptic drinks, as milk-punch, lemonade, porter diluted with water, &c. Snake-root-tea, where it ſat well upon the ſtomach, appeared to poſſeſs moſt advantages in this ſtage of the diſeaſe, inaſmuch as it procured a free determination to the ſurface of the body, independent of its antiſeptic properties; but where the ſtomach rejected every thing, recourſe was had to bliſters, applied immediately over the region of the ſtomach, and, in ſome inſtances, with the moſt happy effects. Spirituous fomentations, applied to the lower extremities, eſpecially where they were followed with perſpiration, in many inſtances gave relief to the ſtomach, and rendered it more retentive.

WHERE the bowels were in a coſtive ſtate, purgative medicines were given to the patient; at the ſame time injections were employed, compoſed of vinegar and water, with the addition of molaſſes and repeated every hour until they produced the deſired effect.

WHEN the functions of the brain and nervous ſyſtem were much diſturbed, as indicated by delirium, ſubſultus tendinum, reſtleſſneſs, &c. ſinapiſms, compoſed of rye-meal, vinegar, and muſtard, applied to the ſoles of the feet, bliſters to the ankles, to the inſide of the thighs, and to the head, in ſome few inſtances procured relief.—In this ſtage of the diſeaſe ſome practitioners had recourſe to bark, wine, and the tonic treatment in general; but the plan I have obſerved to be attended with moſt ſucceſs in addition to the medicines and treatment related above, was to ſupport the patient's ſtrength, by the mildeſt nouriſhment, and ſuch as was the leaſt ſtimulating to the ſyſtem, viz. ſoups, compoſed of a great proportion of vegetables, ſago, milk punch, with a ſmall quantity of ſpirits or brandy, merely ſufficient to render it grateful to the ſtomach. In addition to this mode of treatment, great attention was paid to the removal of every external ſource of irritation, by frequent changes of linen and bedding, by frequently wiping the body with cloths dipped in ſpirits or vinegar, removing every offenſive matter from the room, and by correcting the atmoſphere around him, by the exploſion of gun-powder, ſprinkling vinegar over his bed, and through the room, and procuring a free circulation of freſh air.

Fourthly, Having, by the means above enumerated, procured an entire ſolution of the fever, it remains to reſtore the ſtrength of the ſyſtem. In the ſtage of the diſeaſe alluded to under the laſt indication, while a degree of fever remained, an active tonic or ſtimulating plan of treatment was found injurious; but, when a perfect ſolution of the diſeaſe was obtained, and the patient laboured under mere debility of body, this mode of treatment was not only admiſſible, but, in many inſtances, the patient's ſtrength was ſo completely exhauſted, that the moſt reſtorative medicines and diet became neceſſary. In this ſtate of body recourſe was had to the bark, ſerpentaria, the different bitters, mineral acids, and the uſual medicines preſcribed with this intention, viz. wine, porter, milk-punch, &c. The diet employed with moſt advantage conſiſted chiefly of vegetables: ſago, tapioca, indian and oat-meal gruel, rendered palatable by the addition of wine, were, for the moſt part, grateful to the patients—were ſufficily nouriſhing, and, being of a more antiſeptic quality, were found leſs hazardous than the uſe of animal food. When animal food was employed, it was in the form of ſoups, with a large proportion of vegetables, or calves-feet jelly, with the addition of wine: in this form it became leſs exceptionable. But ſolid animal food was very commonly injurious, retarding the recovery of the patient, and in many inſtances producing a return of the diſeaſe; it was therefore very generally prohibited during the convaleſcent ſtate of the patient.

THE drinks employed with moſt benefit, and which were found moſt grateful to the ſick, were wine and water, milk-punch, porter, &c. Such was the diſeaſe, and ſuch the mode of treatment, as far as has come within my knowledge.