Page:The American Cyclopædia (1879) Volume IV.djvu/526

 CHOLESTERINE tal steward, he was saved when on the bor- ders of a profound collapse, and slowly and steadily brought back to life. All three of these wise and patient men were convinced that the more there was of haste, the more pro- fusely food, stimulants, and drugs were plied, the more certainly fatal would be the result ; and that the more steadily and quickly their few and simple means were used, the greater would be the chances of recovery. When he was cold and almost pulseless, and so exhausted as scarcely to be able to raise a finger or move his head, his courage did not fail him ; and his skilled and wise attendants did not kill him with mistaken zeal and kindness. CHOLESTERINE (Gr. X W, bile, and <rrepc<Jf, firm, solid), or Biliary Fat, a non-nitrogenized organic substance, found in the bile and in other fluids or situations in the human body, or that of animals in which the biliary secre.- tion is prominent, this substance when sepa- rately obtained having the appearance of sper- maceti, and differing from ordinary fats only in the fact that it refuses to form a soap with caustic alkalies, even under the action of pro- longed heat. Oholesterine is neutral, inodor- ous, insoluble in water, soluble in ether and hot alcohol. Its composition is usually repre- sented by the formula CttHttO. It is com- bustible and burns with a bright flame. It crystallizes in very thin, colorless, transparent, rhomboidal plates, frequently marked by a cleavage at one corner in a line parallel with the corresponding side, and often forming in layers, the borders of the subjacent plates showing very distinctly through those above. Cholesterine was discovered in 1782, by Poul- letier de la Salle, in biliary calculi ; its pres- ence in the blood was shown in 1830 by Denis. In a condition of health, cholesterine exists in the bile, blood, liver, brain and nerves, and the crystalline lens. It is also found in very large quantity in the meconium, in the faeces of ani- mals hibernating, and by some authorities it is said also in the faeces generally in health. It occurs frequently as a morbid deposit or product. Biliary calculi consist wholly of cholesterine, coloring matter, and mucus. The tablets of cholesterine are found in or obtained from cancerous growths, encysted tumors, and atheromatous deposits in the coats of the ar- teries, and sometimes as forming distinct de- posits or tumors in the substance of the brain. Cholesterine is obtained also from the fluid of hydrocele, of ovarian cysts, of tubercle in the crude state, and from pus. Its quantity in the normal fluids is small, forming, according to Berzelius, 1 part in 1,000 of the bile in man, and according to Prof. Austin Flint, jr., of New York, only -618 in 1,000. The analyses of the latter give as the proportion in 1,000 parts, for the venous blood of the male, '445 to '751 ; for the meconium, 6'245 ; for the hu- man brain (in two instances in which death was sudden), 7'729 to 1T456. The bile and some other fluids can hold the cholesterine in solution, though by aid of what other con- stituent is not known ; while it may perhaps exist, in organic union with other components, in the nervous substance and the crystalline lens. While the chemical relations of choles- terine had been fully studied, its physiological relations long remained in doubt, or the sub- ject at the most of conjecture. According to the researches of Prof. Flint, cholesterine is constantly forming in the system, being always present in the nervous matter and the blood, but by far the most abundant in the former ; it is a necessary product of the waste of the nervous matter, and being removed thence in the circulation constitutes one of the most im- portant of the materials to be excreted from the body. It is separated from the blood by the liver, appears constantly in the bile, and in this is poured into the alimentary canal. As in the case of urea, the most important excreted matter of the kidneys, so with cholesterine, if its separation and removal through the liver ceases, or is not in due amount, this product accumulates in the system, producing its form also of poisoning or deterioration of the blood, and leading to a corresponding class of dis- eases. Thus the bile has two distinct functions answering to the presence of two entirely dis- tinct components in it. One of these embraces the glyco-cholate and tauro-cholate of soda, which do not preexist in the blood, and so do not accumulate in it when the liver is torpid or its action arrested ; these are produced in the liver, serve a useful purpose in completing the process of digestion, are not discharged in the faeces, and constitute a secretion only. The other function of the liver is the depuration of the blood by freeing it of excess of cholee- terine ; and to this end probably it is that se- cretion of bile continues in the intervals of di- gestion, though more abundant during the di- gestive acts. The ordinary faeces, according to Prof. Flint, do not contain cholesterine, but contain stercorine; the substance thus named by the author being invariably found by him in the normal fseces, and regarded by him as identical with that previously found in minute quantity (*02 to '025 part in 1,000) in blood, and named seroline. The transforma- tion of cholesterine to stercorine occurs during the digestive process ; and that it does not take place before digestion commences, nor when it is for the time arrested, accounts for the presence of the former only in the me- conium and the excrement of animals hiber- nating. Stercorine is therefore the form in which cholesterine is discharged from the body. The facts explain the distinction of the two types of jaundice. In the mild type the bile is formed, but its discharge being obstructed, its coloring matter chiefly is reabsorbed, and the disease is attended with yellowness of the skin, but is comparatively harmless ; in the other, the grave symptoms and almost invariably fatal character are due to cessation of the action of the liver, with retention of choleste-