Page:A Handbook of the Theory and Practice of Medicine - Volume I - Frederick T. Roberts.djvu/91

Rh the presence of which in certain tissues is characteristic of albuminoid disease, is pale, structureless and homogeneous, and at first nearly transparent. It is not prone to decomposition, and is unaffected by most chemical ag-ents, but yields certain characteristic reactions. When a watery solution of iodine is applied to the affected tissue, a deep reddish-brown or mahogany colour is broug-ht out, but this is not invariable even when the disease is advanced, and it may be of more service in indicating a slight degree of the change, especially when the solution is applied to microscopic sections. The subsequent addition of a drop of strong sulphuric acid may develope a violet or dark-blue colour, but this further test, which is recommended by Virchow, is not easily obtained and is unnecessary. The albuminoid substance may undergo a granular or fatty degeneration, and it is also said that it sometimes tends to contract and to become changed into fibrous tissue.

When an organ or tissue is the seat of marked albumanoid dis- ease, it presents certain striking characters. The organ is en- larged, sometimes to a great degree, but without any irregularity in form or outline, the surface being quite smooth, and the margins inclined to be rounded. The weight is proportionately increased ; the specific gravity is high ; and the organ feels heavy, solid, and firm. It may be cut into regular fragments, quite smooth and pre- senting sharp margins ; or very thin slices may easily be removed. It can also be torn into pieces, while the consistence is peculiar, presenting a combination of toughness and resistance with elas- ticity, resembling somewhat that of wax, or wax and lard combined — hence the names waxy and lardaceous. A section is dryish, paler than normal, anaemic, and presents a glistening and translucent aspect, being quite smooth, uniform, homogeneous, and compact. In many instances, however, the mischief has not extended to such a degree as to alter much the general physical characters of organs; and it may be limited to the vessels or to certain spots, as is well seen in the so-called "sago-spleen," in which the material is confined to the malpighian corpuscles. In still less advanced cases the change may only be detected by examining sections of the aff"ected tissue under the microscope, and to these, well- washed, the iodine test may be applied. The minute arteries and capillaries are almost always first involved, especially their muscu- lar coat, and the cells of their inner coat. The walls become

Fig. 8.

Liver-cells infiltrated with amyloid matter, a. Isolated cells ; b. A fragment of the secret- ing network in which the boundaries of the individual cells have ceased to be visible. (Rindfleisch).