This constitution of the blood is characterized by deficiency in fibrin but preponderance of albumen, and generally speaking, also of blood-globules. The blood is upon the whole thickish, tenacious, dark-red, and contains, if any, only a few soft, gluey or jelly-like coagula, in which there is much cruor pent up.

It has a very extensive domain, comprising a vast number of special erases, which reveal their kindred nature by the general characters of the blood just defined, by the metamorphoses which many of them undergo in common, and by the general sameness of their products; whilst again they differ in some particular attribute of the latter, and by specific relations to particular textures and organs [localization].

Their range comprehends the most important and most perilous, acute and chronic diseases; plethora [general hyperemia], venosity of the lungs, and heart diseases, the acute exanthemata, especially scarlatina and measles, the so-called substantive fevers, chronic rheumatism and gout, rickets, typhus, Asiatic cholera, so-called acute tuberculosis, Bright's disease, and lardaceous degeneration of the liver, spleen, or kidneys, mollities ossium, cancer, the crases of acute convulsions, of tetanus, of hydrophobia, diseases of the nerve-centres, chronic mental alienation, hypochondriasis, chronic metal-poisoning, especially with lead, narcotism, finally the erases accompanying atrophy after acute, exhausting diseases, the so-called suffocative death-seizures generally.

To discover the nature of the special crasis in so heterogeneous states, is reserved for the future, and rather for chemistry than for anatomy.

Many acute erases issue in septic destruction of the albumen and putrid decomposition of the entire blood-mass. This consummation is especially frequent in the exanthematous and the typhous erases, and in acute convulsions. The acute erases are moreover liable to frequent transformations, especially to the croupous crasis and to pyaemia. There occurs frequently an acidifying of the blood, which localizes itself in miliary eruption and in acute softening of the stomach.

The crasis is sometimes protopathic, - habitual, persistent, ingrained in the individual, or acute and evanescent. At other times it is deutero-pathic, or the sequel to exhausting and especially to defibrinating disease. It is, moreover, a primitive blood-disease, called forth by poisons, by miasma, by contagion, or else it is consecutive to disease of solid parts [for example, organic heart disease], and determined by neurosis.

The products placed under its control [exudates and new growths] are distinguished by an excess of albumen, by very subordinate coagulability, by lack of disposition to become organized, by persistence at embryonic grades of structural development.

A not unfrequent sequel to extensive exudation is hydraemia, or, it may be, tarlike inspissation of the blood with anaemia. The former becomes developed without any notable serous effusion, the water being otherwise disposed of in the morbid process. The anaemia is commonly due to a shattered condition of the nervous system.

Several of these acute crases have a decided relation to the mucous membranes, and especially to their follicular apparatus, to the lymphatic glandular system, to the common integuments, to the spleen. The dead body presents, especially in the acute crases, dark coloration of the common integument; rapidly developed, extensive, and very dark death-patches; early decomposition; a very marked but for the most part evanescent rigor, and a lax, doughy condition of the parenchymata. Hyperemia and stases arising in the different organs, not unfrequently become exalted into hemorrhage. In the tarlike inspissation of the blood, the corpse is in a high degree emaciated or rather shrunken, dry, - the common integument, of a lead-color, or livid.

Let us endeavor to submit the more important of these erases either singly, or where the distinctions are not very marked, more collectively, to an anatomical muster.

(A.) Plethora

It is characterized by excess of blood, by a preponderance of the blood-globules over the fibrin, by a deep red, tenacious blood. It involves the direct manifestations of venosity in the inverse ratio of the amount of blood which the organism is capable of arterializing. It occurs under two opposite and contrasting relations. First, in conjunction with florid nutrition of the textures, fulness of muscle, and especially ample areolar tissue and fat formation. Secondly, as a very marked phenomenon in union with general emaciation, - wasting of the solids [so-called nervous tabes]. Under the latter circumstances, it is observable both in very delicate children, during the first months of their life, and in insane adults [in hypochondriasis, melancholia, &c]

In the dead body, the general overloading of the vascular system, and occasionally surpassing hyperaemia of various organs, especially of the lungs or of the brain, or of the liver and entire portal system, are manifest. According to the degree of intensity of the crasis, all of the soft parts are more or less deeply colored. In the emaciated, the common integuments exhibit vast patches of a purple, or of a bluish leaden hue.

Plethora predisposes to congestion, to hemorrhage, to blennorhoid, albuminous, and serous exudations of greater or less moment in proportion to their amount and to the importance of the organs concerned. In corpulent, square-built [apoplectic] individuals hyperaemiae of the lungs are frequent. In these the plethora often of itself, but more commonly through acute serous effusion into the bronchia and lung-cells, proves speedily fatal. Moreover, the plethora occasions dilatation of the heart, with subsequent, progressive augmentation of its substance [hypertrophy].

(B.) The Typhus-Crasis

It compasses the entire nature of typhous disease, and is at the root of all its phenomena, whether of substantive change or of functional disturbance.

The typlius-crasis is marked by the destruction - the diminution - of the fibrin, and the comparative preponderance of the blood-globules. The typhus blood is in various degrees fluid, and of a deep purple color. It forms, if any, but scanty, loose, soft, and humid, deliquescent coagula, reddened by the imbibition of pigment-holding plasma.

The corpses of typhous individuals are remarkable for the deep, dingy, bluish-gray coloration of the common integument, for the deep purple of the death-spots, for the dark russet hue and the rigidity of the muscles, and for the dryness of the areolar tissue. The serous membranes, and especially the peritoneum are of a dull gray, lack-lustre, and occasionally suffused with a tenacious humor. All the textures in contact with blood appear discolored from imbibed haematin, of a peculiar shade, verging from violet color upon brown.

In the next place, the multifarious local hypersemise have to be noticed. They are due to the paralyzing influence of the blood upon determinate ranges of the nervous system, either at the periphery or at the centres. Foremost amongst them are local hyperaemise of the mucous membranes, of the lungs, of the brain, and its membranes, of the spinal cord, of the common integuments. They often display the attributes of so-called hypostasis. Upon mucous membranes they frequently degenerate into hemorrhages, which occur also, although far more rarely, in parenchymata, for example, in the brain.

The typhus-crasis manifests a very marked relation to mucous membranes, especially to the lymphatic glands and to the spleen. In middle Europe it is the mucous membrane of the intestine and especially of the ileum, rarely the bronchial mucous membrane with the lungs and the bronchial glands; in the North, it is rather the last mentioned, namely, the respiratory tract; in the South [in pest-typhus], it is the peripheral lymphatic gland system, in which the crasis becomes localized. In the form of a typhous inflammation it determines, in the follicular apparatus of the ileum and in the mesenteric glands, a peculiar marrow-like product, which, in intense cases, closely resembles medullary carcinoma.

The very variable consistency of the typhus-substance points to variations in the typhus-crasis itself; to different degrees of plasticity in the typhous blood-plasma.