5. Lime-Salts

(a.) Basic phosphate of lime, as a gelatino-granular mass, soluble in acids. It occurs both in fluids and in solidified formations, in a soluble combination of protein-substances, with gluten, out of which it separates - especially in the shape of cretefaction and ossification - in the form of molecule.

(b.) Carbonate of lime, in the shape of granular deposition, - in the cell-incrustation, of stratefaction - either alone or in union with the foregoing substance. Soluble in acids, with effervescence.

(c.) Oxalate of lime, in octohedral crystals, sometimes remarkably minute; insoluble in water, alcohol, ether, acetic acid; soluble in hydrochloric acid. Found in the urine.

6. Ammonio-Phosphate Of Magnesia

Ammonio-Phosphate Of Magnesia, in crystals of various shapes. When rapidly formed, they cluster together in stellate groups of needle-shaped crystals, or represent denticulate, leaf-like forms. When slowly developed, they constitute trilateral prisms, in which both angles corresponding to the same lateral-edge are truncated. The crystals are readily soluble in acids - even in acetic acid. The occurrence of this salt is extremely frequent. Wherever a development of ammonia takes place, the wide dissemination of phosphate of magnesia determines the formation of the insoluble triple phosphate.

7. Sulphuret Of Iron

Sulphuret Of Iron, in molecular granules, soluble in acids and pre-cipitable out of these by means of sulphuret of soda.

Such are the principal and the better known substances which, independently of, or in combination with, others, compose the bulky unorganized formations, as so-called concretions or concrements. We shall treat of these generally; dividing them into two great series, namely:

1. Into such as are essentially protein-substances; or into such as consist of gluten or horn-like substance, of fat, and, lastly, of the phosphates and carbonates of lime and magnesia; it matters not whether the latter be directly thrown out as such, or whether they have, as usual, become obviously developed out of the former, that is, out of the protein-substances.

2. Into such as have comparatively a varied composition, and are marked by the specific substances which they contain.

First Series

(a.) Protein concretions, as coagulations within the bloodvessels - vegetations; as exudates in parenchymata, upon membranous surfaces; as free bodies in serous cavities, tubercle, etc.

(b.) Accumulations of gluten-like, colloid substance, commonly within cyst-spaces; and cornified protein concretions, for example, of the valve-vegetations in the heart.

(c.) Fat, as the cyst-contents; or as accumulations within serous cavities; in parenchymata, in the shape of spherical or irregular masses. Frequently in combination with the following, namely:

(d.) Bone-earth concretion, so-called cretefaction and ossification, as developed, not alone in the protein and gluten-holding unorganized basements already adverted to, but also in fibroid and cartilaginous textures, in a mode and form which, together with their relations to the normal ossification of bone-cartilage, we have discussed in another part of this volume. [See "Bone Formation".

The concretions consisting of lithate of soda, found in the sheaths of tendons, within capsular ligaments, even in the spongy texture of the articular terminations of bones, constitute an exception only as regards the nature of the substance itself.

The significance of concretions of this series differs with the organ affected; thus, concretions on the heart's valves are, perhaps, the most important of all.

Second Series

To this series belong the concretions in and arising from fluids of secretion. We divide them into two species:

(a.) They result from the precipitation of one or of several of the specific components of a secretion, animal matter entering into their composition for the most part only in small quantity and by way of a bond medium.

They constitute the genuine stony concretions or calculi, which, when diminutive, are termed gravel or sand.

The size of calculi is, as may be inferred from what was just stated, extremely various, from that of a fine, just perceptible sand-grain, to that of a concretion filling up the largest secretory canals and reservoirs.

In smaller, solitary concretions the form is mostly the spherical; - in larger ones, it corresponds to that of the said canals and reservoirs, as in the instance of renal calculi, and is subject to much modification. Where many concretions co-exist, they acquire from reciprocal pressure and friction, the most varied, polyedrical shapes, - as in the case of urinary calculi, and especially of gall-stones. Their surface is smooth, polished, or else knobbed and uneven, stellate, thorny, rough.

Their consistence mainly depends upon their chemical composition.

They reside at large in their respective cavities, or else, filling the latter, they lie firmly impacted. Or again, they adhere as if glued or soldered at some point, through the medium of fibrinous exudate.

Their structure varies extremely. At their nucleus they exhibit an agglomeration of an amorpho-granular precipitate. Or again, they consist of concentrical strata of the same character, or else of a crystalline precipitate; or lastly, they are altogether of crystalline fabric, as in the case of certain lithic acid calculi, but particularly of cholesterin concrements in the gall-bladder.

The first impulse to their formation is sometimes given by foreign bodies introduced from without, or by coagulate, - endogenous products. The concretions represent, in the first instance, incrustations of things in various degrees alien to their composition. Thus, for example, on the one side, a great variety of foreign bodies which have lapsed into the urinary bladder, give rise to lithic acid calculi; on the other side, inspissated bile, or bile-pigment, to cholesterin calculus in the gallbladder.

To this category belong lithic acid calculi, salivary calculi, lachrymatory calculi, prostatic calculi, gall-stones, many intestinal concretions.

(b.) They are due to the inspissation and desiccation [through exos-mosis or evaporation] of some fluid of secretion either within or externally to its secreting canals and cavities. Here the concrement consists of the ingredients of the secretion in their totality, including, of course, a considerable amount of so-called animal matter, and with it of organized elements. Proportionately to the degree of inspissation, the concrement is soft; or, it may be, of a stony hardness. Concretions of this kind very often become developed in cyst-like dilatations of the follicles, in which the secretion accumulates and stagnates, and the inspissation of the contents of encysted tumors of new formation, applies here in its most extended sense. The physical and chemical properties are, it will be readily conceived, extremely inconstant and variable.

This group comprises concretions in the follicles of the skin, in mucous follicles, in the tonsils, in the nasal and pharyngeal cavities, upon the glans and prepuce, and certain intestinal concrements, especially those occurring in diverticula; finally, the inspissations of colloid, and of other cyst-contents.