Page:The American Cyclopædia (1879) Volume I.djvu/280

 256 ALBUMINUKIA coagulum may be redissolved by the action of the alkali. In the blood, the albumen is re- garded as its most nutritious ingredient, being employed for the nourishment of the various tissues, by which it is absorbed and afterward converted into materials similar to their own. It is not discharged from the body under its own form with the excretions, except hi cases of disease, but is retained and employed for the maintenance of the vital operations. Albumen is regarded as the representative of a large class of organic substances, as well vegetable as animal, which are known as the albuminoid substances. (See ALIMENT.) They are distin- guished by the facts that they all contain nitrogen, in addition to carbon, hydrogen, and oxygen ; that all those which are fluid or semi- fluid are coagulable by various means ; that they are very ready both to excite and to un- dergo indirect or catalytic transformations; and that they are all susceptible of putrefac- tion. They enter very largely into the compo- sition of the food, and constitute its most val- uable and nutritious ingredients. According to recent researches (1865) of Hoppe-Seyler, there is a marked ditference between the albumen of eggs and that found in other parts of the ani- mal economy. Vegetable albumen has never yet been prepared in a pure form, and we are unable to say whether it may not constitute a third modification. The two modifications known to chemists at the present time are the soluble and insoluble. AUtnil.M'lll.t, or Bright's Disease, a disease characterized by the presence of albumen in the urine, a more or less general dropsy both of the cellular tissue and the internal cavities, and an organic change in the substance of the kidneys ; so called from the name of its discoverer, Dr. Bright. The acute form of the disease some- times commences with a chill, followed by more or less fever, with a dry skin, furred tongue, and frequent pulse. In other cases the atten- tion of the patient is attracted by the swollen state of his countenance ; the swelling rapidly extends and becomes general ; at the same time the urine is greatly diminished in quan- tity, and is of a dark color, looking as if im- pregnated with smoke, or red, and evidently containing blood. There is more or less dull pain about the loins, with a dry pallid skin, thirst, disinclination for food, often nausea and vomiting. Sometimes, though happily not often, there is complete suppression of urine. In such cases, as a rule, fatal coma quickly supervenes. In the course of the disease, effu- sions into the cavities of the pericardium, the pleura, or the peritoneum, with or without inflammation of those membranes, are apt to occur ; or epileptic convulsions may come on, often ending in fatal coma. The urine has commonly a specific gravity of from 1*015 to 1'025 not varying much from its ordinary standard ; when tested by heat and nitric acid, it shows the presence of albumen, sometimes in such large quantity that the whole of the fluid is converted into a jelly-like mass. When examined under the microscope, the sediment deposited by the urine, on standing, is found to consist of blood corpuscles, of renal epithelium, and of small fibrinous casts of the uriniferous tubes, containing entangled in them epithelial cells and blood globules. After the disease has continued some weeks in adults, the epithelial casts, as they are termed, sometimes contain a few oil globules ; if the patient recover, these gradually disappear as convalescence comes on. On post-mortem examination the kidneys are found to be enlarged, and gocged with blood. Sometimes their exterior is pale, and this pale- ness extends through the cortical substance, particularly in the cases which follow scarlet fever. Microscopic examination shows many of the convoluted tubes to be crowded with epithelium, especially in those parts of the cor- tical substance which appear pale to the naked eye. Of the causes of acute albuminuria, ex- posure to cold, particularly when the body is exhausted by fatigue, by recent illness, by an innutritions or unsuitable diet, or by excessive indulgence in alcoholic liquors, is undoubtedly the most important. The actions of the skin and of the kidneys are always to some extent vicarious of each other. When there is free perspiration, the quantity of urine is dimin- ished; in cold weather it is increased. In these cases, however, it is only the watery parts of the excretion which are interfered with ; and the kidneys continue to free the blood from the excrementitious matters which it is their peculiar function to separate. When disease follows exposure to cold, it is probable that the sudden checking of the function of the skin produces a vascular congestion of the kid- neys, an increased pressure of the blood in their vessels, and thus the appearance of albu- men in the urine. Other diseases in which the blood is in an altered condition are occasionally attended or followed by albuminuria ; thus re- peated instances of its occurrence have been met with in connection with acute rheumatism, typhus fever, erysipelas, and purpura. During the desquamative process in scarlet fever, the patient is liable to acute albuminuria. Accu- rate observers have found that in most cases albumen can, at some time of the later period of the disease, be discovered in the urine. If at this time the patient be incautiously and un- duly exposed to the influence of cold, disease of the kidneys attended by dropsy is apt to fol- low. The attack differs in no respect except its cause from the acute albuminuria which occurs under other circumstances ; it has sim- ilar symptoms, and post-mortem examination reveals similar appearances. The strumous diathesis predisposes to the disease ; cases of scarlet fever in children of that diathesis have always to be watched most carefully, and from the ordinary causes of albuminuria the strumous suffer in large proportion. It is easy to under- stand the pathology of the disease. Not only is the urine diminished in quantity, but what is