Irrespectively of all other anomalous coloration, but with a retrospect to that conversion of blood-pigment alluded to under the head of hemorrhage, we shall here treat of granular pigment. It appears under the various shades of jet, of Indian-ink black, of russet, or of a yellow-brown.

It occurs both free and enclosed within cells, in the shape of very small, spheroidal, scattered or clustered granules, together with rod-like molecules (with molecular motion), or else in the shape of larger spherical or spheroidal, in like manner either scattered or intimately grouped and blended corpuscles. The cells are for the most part spherical, but in certain conditions, as in cancer melanodes, spindle-shaped, caudate, rarely twigged.

These various modes of occurrence, together with the several shades of the pigment enumerated, are, as we shall afterwards see, partly phases of development of the pigment, partly due to external conditions.

It hardly ever occurs quite pure between the elementary parts of a texture. Generally speaking, it adheres to a blastema at some period of textural development, for instance, to inflammatory products, adventitious membranes, colloid, malignant growths (melanosis).

When small in quantity and equably distributed, it determines slate-gray coloration of the textures, or a speckling or streaking with black dots. It may, however, manifest itself in larger knotty accumulations so as to consolidate and lay waste the textures, as for example in the lung.

It affects the fluids also.

Before speaking of its origin, it is requisite to pass in review, as a simple series of facts, the several cases of its occurrence.

In normal textures, the sequence of its amount and frequency is nearly as follows:

1. In The Lungs

In The Lungs, its seat is the true pulmonary texture, but also the interlobular areolar tissue. When inconsiderable in quantity, it lightly marbles the parenchyma. When abundant, it forms greater, branched accumulations, and along with these, distinct solitary masses of from a hempseed to a bean in size, and presenting a cut surface of dull metallic lustre. Or, again circumscribed patches of the parenchyma, especially at the apex, may be so replete with it as to display it as a coherent, black, hardened, impervious mass. It is particularly redundant around shrivelling, cretefying tubercles, healing cavities and cicatrices at the apices of the lung. It is for the most part found pure, free, in the shape of a minute molecule, unattached to any ostensible blastema, and certainly very seldom contained within cells.

In manhood and old age it is but a physiological product. In the earlier periods of life alone, as those of boyhood and youth, or when by its quantity it proves destructive to the pulmonary texture, is it to be regarded as a morbid phenomenon. The notion of its being peculiar to old age is correct only in so far as, in the aged, it is for explicable reasons hardly ever absent. It does not, however, by any means belong exclusively to this period of life. If it almost invariably abounds in the old, it is because in them there has been ample time for its accumulation. Still it is undeniable that the condition of the blood in advanced age, with its augmented proportion of blood-corpuscles, and its simultaneous diminution of fibrin, must essentially favor the deposition of this substance.

2. In The Bronchial Glands

In The Bronchial Glands, from a speckling and extensive marbling up to the point of considerable increase of volume in the gland, and its conversion into a hard Indian-ink-colored tumor, in which the glandular parenchyma has perished. Its amount is here commonly proportionate to that in the lungs. Its form is that of free molecule, very rarely of molecule contained within cells.

3. Gastric And Intestinal Mucous Membrane

In the shape of free molecules, often coherent in larger masses. It occurs thus both in the muco-membranous texture itself, more particularly at the great concourse of the solitary and of the aggregate glands, as also in the intestinal villi, imparting to the mucous membrane an aspect, to the naked eye, of being lightly brushed over with black, or uniformly tinged of a slate-gray. Where the accumulation of pigment is considerable, the part appears of a blackish gray, or it may be of a deep black.

In rarer instances, the tracheal and bronchial mucous membrane is pigmented - that of the uterus frequently.

In the majority of cases it accompanies the more intense chronic catarrhs (blennorrhoeae) of the stomach and intestines. When affecting the intestinal glands, it points to antecedent hyperemia, stasis, and exudation - typhus, for example, - at every age, even in delicate children, to a diarrhoea-like process in the follicles of the colon.

4. In The Mesenteric Glands

In The Mesenteric Glands, it is for the most part limited in amount, and concurrent with pigment in the intestinal mucous membrane. Here, again, it is a sequel to typhous hyperaemia and effusion.

In other lymphatic glands, the seat of hyperaemia, hemorrhage, inflammatory stasis, and exudation, it is less frequent.

5. In The Central Ganglia

In The Central Ganglia of the abdominal sympathetic, more especially the ganglion of the solar plexus, usually combined with wasting thereof, as a sequel to typhous hyperaemia. For the most part small in quantity, has a uniform, pale, slate-gray coloration, or is visible as blackish dots or striae.

6. In The Common Integument

In The Common Integument, as the so-called melasma of the old or cachectic, as a diffuse suffusion of the common integument with pigment, in the lower extremities, and as knotty pigment accumulations in the face.

In New Growths

1. In the blood-coagula in arteries, veins, and capillaries (metastases), whether spontaneous or due to inflammation of their coats, and terminating in their transmutation to fibroid shrivelling cords and cicatrices.

2. In atheroma that has discharged itself into the canals of arteries, and especially in the depots and cicatrices formed in the act of its excretion.

3. In the membranaceous growths investing hemorrhagic depots, as also in the contents of hemorrhagic cysts, being here of a russet or yeast-color. The black pigment found in the shrivelled and extinct ovarian follicles, after elimination of their contents (during menstruation), is here deserving of mention.

4. In inflammatory products upon serous membranes, as a black pigment, upon the peritoneum, more commonly of a brown, or rust-color upon the tunica viginalis testis, upon the pleura, the pericardium, the arachnoid. It adheres to the exudate from the commencement, that is, from its crude condition, through all its phases of textural development, up to the areolar or the fibroid structure. According to its proportion, it manifests itself as spotted, striated, or uniformly slate-gray, bluish-black coloration, - always occurring as free pigment molecule.

It is more rare in the inflammatory products of parenchymata. Scar-textures are, however, not exempt from it, even in the common integuments.

To its appearance on serous membranes we have to add that detected upon the inner membrane of cysts, and of the cyst-like developments of various hollow organs and canals - for instance, upon the inner surface of the dropsical Fallopian tube sac.

5. In tubercle, that is to say, the hemorrhagic tubercle, both in paren-chymata and upon serous membranes.

6. In colloid, - mostly as a brown tint.

7. In cancer melanodes (commonly called melanosis, malignant melanosis), a heterologous growth, consisting of medullary carcinoma with pigment. The brown and black pigment is here partly free, partly contained in cells, with the character of cancer cells. The medullary carcinoma is in various degrees spotted or striated with the pigment, or, in fine, so replete with it as to appear throughout dark brown or black. (See Cancer melanodes).

In Fluids

1. In the fluid portion of the exudate in serous sacs.

2. Mingled with the contents of the larger cysts, and of hollow organs in process of cyst-like development; for example, the dropsical tube-sac.

Finally, it occurs under several special conditions, as:

1. In the black substance present in acute softening of the stomach; in the black contents of the stomach and intestines generally.

2. In the pulp constituting the rare black softening of the spleen.

3. In the detritus of necrosed textures, especially in dry gangrene, or mummification.

4. In the parietes of ill-conditioned abscesses - ichor depots; but most of all at the margin and base of every variety of intestinal ulcer.

This preliminary will serve as a useful starting-point for an inquiry as to the groundwork of pigment, and the conditions upon which its appearance depends.

That the groundwork of pigment is the coloring matter of the blood appears to us proved, the cases in which pigment is obviously derived from hcematin and blood-corpuscles being so numerous as to exclude all doubts on the subject. Still the circumstances by which the conversion is brought about, and still more the various shadings of the pigment, are unexplained.

The cases in which the metamorphosis of blood-pigment - that is of blood-corpuscles into pigment - is manifest, are of the most common occurrence. Such are the cases of hemorrhage, and of hemorrhagic exudates in serous sacs, more particularly the peritoneum, of hemorrhage from intestinal ulcers, of pigment development in blood-coagula within vessels, of black or dark-colored softening of the stomach, of black contents of the stomach and intestines generally, etc.

But hemorrhage, whether simple or combined with inflammatory exudation, cannot, in all instances, be assumed, still less proved. In the other cases, therefore, where pigment occurs, for example, in the lungs, the lymphatics, etc, we must, whilst still holding on to the belief that haematin furnishes the groundwork of the dye, look around us for some further mode of elucidating the mystery.