The causes of phlegmonous inflammation are very various, but they may be classed into me chanical and chemical. Fevers frequently give rise to it. An individual phlegmon is sometimes pro duced by the irritation of extracting one of the bulbs of the hair. The alternations of temperature is a very common cause, especially when the con stitution is not in a healthy condition, either from irregularity of the bowels, intemperance, or distress of mind. The operation of cold on the system in producing inflammation has long been an interest ing investigation. When an intense degree of cold is applied for a short period to a part of the surface of the body, it paralyses or arrests the action of the nerves for a time, and also constringes the blood vessels, which causes a reaction of the contiguous nerves and arteries to overcome this torpidity and obstruction, and produces an effusion of the serous part of the blood between the cutis vera and cuticle. When this intense degree of cold is sustained for a length of time, both nerves and blood-vessels are so overpowered, the former rendered so torpid, and the latter so constringed, that too often they are un able to recover their vitality; and in some instances, even life is destroyed, when congelation of all the structures of the body is the result. According, therefore, to the continuance of so severe a degree of cold, will either inflammation, with recovery of the frost-bitten part be the result, or inflammation with mortification of the part; consequently, on the same principle will a more moderate degree of cold only produce inflammation. In the last case, the nerves are merely chilled or impeded in their func tions, while the arteries are constringed, so that re action is the result, or inflammation is produced. Inflammation of the throat, chest, or belly, arising from wet feet, appears to depend on those cavities being more delicate, sensitive, and vascular in their structure, cxteris paribus, than the rest of the body, or from one of these parts having been for merly attacked with inflammation; for it is a sin gular fact, that when any part has once suffered from inflammation, it is liable to a relapse from every exposure to cold; erysipelas of the face is pro bably the most familiar example. The cold must be transmitted from the feet to these organs through the medium of the nerves, and must at first pro duce such a commotion in the nervous and vascular systems as to threaten general fever, for it is more than probable, if inflammation of these organs did not take place, fever would ensue. This effect of cold must occur more readily when there is any ir regularity of the constitution.
Phlegmonous inflammation is said to have its scat in the cellular membrane, but this is evidently incorrect, unless this texture be allowed to form the substratum of all the other structures of the body. This phlcgmonous variety generally terminates in suppuration; sometimes, however, in resolution, but seldom or never in mortification.
It has already been mentioned, that phlcgmonous inflammation is often so diffused as to involve both the nervous and circulating systems, and constitute inflammatory fever, or synocha, or cauma. See Article MEDICINE.
Its treatment consists in local and general blood letting, active purging, tobacco enemata, warm bath, low diet, perfect rest, and the apartment kept darkened. Blood is to be abstracted from the system by the lancet, which may be employed either to open a vein or artery, and the blood should be allowed to flow until fainting ensues, or a marked effect is produced on the constitution; a check must be given to the increased action of the nervous and circulating systems; for it is of no avail in an active disease such as this, to bleed without producing a decided effect on the system.
Whenever the constitution has rallied from the ef fects of the first bleeding, which generally happens in four or six hours, if the violent symptoms are not very materially subdued, a second bleeding should be repeated and carried also to syncope; but much depends on the period of the fever at which blood-letting was first adopted, for it is a law in acute diseases, to modify venesection according to the duration of the disease ; further bleeding may be even necessary, but the quantity required then to produce fainting, will generally be very small. Syncope takes place more quickly in the erect than in the horizontal posture, but it the fever be severe, the patient is unable to be raised, even to the sitting attitude.
Besides venesection from the general system, it is generally requisite to abstract blood locally ; when the head, for instance, is much affected, leeches or cupping glasses ought to be applied to the temples or nape of the neck. Immediately after the first bleeding, a brisk cathartic of calomel and jala• should be given, and if this does not operate in five hours, a tobacco enema of 15 grains to the pint of water should be administered, and after wards a dose of the sulphate of magnesia. When the nausea of the cathartics has subsided, the pa tient should be immersed in a warm bath between 90° and 100° of Fahrenheit,and remain until nausea, syncope, or perspiration occurs. Effervescent draughts may be given every two or three hours. Acidulated drinks may also be allowed, and low diet, consisting of plain boiled vegetables, ripe fruits, farinaceous substances, weak tea with a little milk, and toast water. If the local injury will not admit the patient to be removed into a warm bath, a vapour one may be used while he remains in bed.
In idiopathic inflammatory fever, when all in creased action has been subdued, the diet should be gradually and carefully rendered more nutritious ; but in the symptomatic, it may generally be in-. creased more quickly, particularly if suppuration has commenced.
Venesection acts upon the system by diminishing the sensibility of the heart, first by removing a por tion of the stimulus to the brain, and secondly by lessening the quantity of the stimulus to the heart itself; but this does not always occur in proportion to the quantity abstracted, for some faint from the loss of a very small portion, while others are able to bear the removal of a much larger quantity, and this difference seems to depend on the firmness or flabbiness of the fabric of the individual. In the lean frame, pressure seems to he kept up between the different structures of the system ; while in the loose and flabby individual, pressure or support is deficient, in consequence of which, fainting takes place sooner than when the patient is of a firm habit of body ; upon the same principle, a person faints sooner from being bled in the erect, than in the horizontal posture ; the blood cannot be pro pelled so quickly and easily to the brain, which or gan being deprived of its wonted support or pres sure, and also of its stimulus, is unable to perform its functions, and fainting consequently is the result; but apparently more from the want of support than stimulus, a fact which is corroborated by the phe nomena in paracentesis abdominis for dropsy of that cavity, and also by leaping suddenly out of bed in the morning, or in raising a patient too quickly after fever, or long continuance in the horizontal posture.