Licence: Public Domain Mark
Credit: A text-book of pathology / by Alfred Stengel. Source: Wellcome Collection.
Provider: This material has been provided by the Royal College of Physicians of Edinburgh. The original may be consulted at the Royal College of Physicians of Edinburgh.
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![Pathologic Physiology.—Various views are held to ex- plain the depositions. An excess of the salts in the blood or tissue- licpiids must be rare. On the one hand, it has been assumed that the soluble are converted into insoluble salts, and, on the other hand, that the tissues have become less solvent for the salts. Probably the best established view is that the salts are precipi- tated as insoluble combinations with pi'oteids. Calcareous deposits are probably never I'emoved, but once formed I'emain permanently. There is no doubt that they in- fluence the adjacent tissues to degenerations. OSSIFICATION. Ossification implies the deposition of lime-salts and other changes through the agency of osteoblastic cells. It occurs in cartilages, and in tumors connected with the bones, cartilagae, and periosteum. The salts are more regularly deposited and are usually in masses between the cells. An accurate differentiation from calcification can in some instances be made only by the detection of osteoblasts after decalcification of the material. URATIC INFILTRATION. Deposits of urate of sodium in the cartilages and fibrous tissues of joints and in various other situations occur in the course of gout (see Disturbances of Metabolism and Diseases of Joints). PIGMENTATION. According to the origin and variety of the pigments, pigmenta- tions may be divided into four groups : 1, those in which the pig- ments are derived from external sources; 2, those derived from the hemoglobin; 3, those derived from the bile; 4, those derived from cellular activity within the organism. Pigmentation from the Exterior. Of the first group, those caused by entrance of foreign bodies througii the air-passages are the most important. The condition- now generally termed pneumonokoniosis is commonly a disease of occupation. Coal, iron, and stone are the most frequent foreign substances inhaled. Vegetable particles, as grain-dust and textile fibers, and animal hairs and furs are not uncommonly the cause of such pigmentations. Corresponding to the agent, there are such terms as anthracosis (coal-dust pigmentation), siderosis (iron), cal- cicosis (stone), etc. (Fig. 19). Inhaled substances i)robably do not reach the alveoli, but are caught by the bronchial cellular cilia. In ])art they are coughed up or otlier\vis(; cast off with the bron- chial secretions; in part they penetrate the broncliial walls or are](https://iiif.wellcomecollection.org/image/b21981668_0085.jp2/full/800%2C/0/default.jpg)
