CAL'CULUS, or STONE. In medi•ine, a hard toncretion formed within the animal body, in consequence of the deposition in the solid form of substances which usually remain in solu tion. (See CONCRETION.) The concretions most commonly termed calculi are those formed in the kidney's or bladder (urinary calculi). and those formed in the or biliary ducts (binary calculi). Both of these give rise to very painful symptoms, and may even threat en life. Binary calculi. or gallstones, may gen erally be presumed to exist when excessively severe pain suddenly arises in the right side, beneath the border of the ribs, and when in a few hours jaundice comes on, showing that. some obstruction has existed in the outward How of the bile. But the absolute proof that these svmptoms depend on calculus is often wanting. The pain is, fortunately, transitory. but is more severe while it lasts than almost any other known form of suffering, unless it be that of a calculus in the kidney and ureter. It may be relieved by large doses of opium, but time remedy requires to lw cautiously given, as even in medical hands fatal accidents have occurred. Gallstones, when impacted in the duets, have sometimes proved fatal ; but much more fre quently they find their way. sooner or later, into the intestines. They are almost invariably composed of cholesterin (q.v.), with coloring matter and mucus arranged in layers in a semi crystalline disposition. In size they vary from that of a small gravel to a diameter of over half an inch.
Urinary calculus occurs at all ages, hut is most common in advanced life and in the male sex. It is very frequent in gouty persons, or among those who pursue sedentary occupations and live freely. It is rare among those who live much in the open air, or who take much violent exercise and use little animal food and wine. Among sailors it is peculiarly rare. In certain parts of England the disease is said to he frequent, as in Norfolk; and perhaps along the eastern coast of Scotland. In India, too, where some of the predisposing circumstances men tioned above can hardly be said to prevail, stone is by no means uncommon. The predisposing causes of calculus are still very imperfectly un derstood. In its early stages the condition usu ally presents itself in the form of gravel, shown by the passage of numerous very small portions of gritty concretion, which may be observed in the urine as a deposit like sand or like small grains of ('avenue pepper. When such deposits occur frequentl•—especiall• if they are present at the time of passing the urine, and not merely after it has cooled — there is reason to apprehend the subsequent formation of calculus. tf, in
these circumstances. there are pains of a dull character in the loins, with occasional sharper twinges, no time should be lost in seeking medi cal advice. If a tit of very severe pain should occur in a person for some time affected with gravel: if the urine becomes bloody: if agoniz ing twinges, commencing in the loins, radiate downward into the thigh or the groin. it is probable that a stone has already formed in the kidney. and is being displaced toward the blad der. Calculus in the bladder is at first attend ed with little suffering, as compared with that caused by the stone in its passage downward from the kidney; but unless removed or evacu ated, the calculus is sure to enlarge, and it then hOe0111PK the cause of tme of the Host pain ful diseases that afflict humanity. The exist enee of a !Acme in the bladder, however, should never be assumed without a surgical examina, Lion, as all the symptoms are deceptive in cer tain cases. The most striking (and. perhaps, the most trustworthy) evidence of stone in the bladder, apart from the testimony of the sound (see Liznozomy), is smarting and burning pain experienced after the bladder has been emptied, together with occasional temporary stoppage in the flow of urine. The correct appreciation of all the symptoms, however, demands the famil iarity with such cases that comes from surgical experience.
The chief varieties of urinary calculus, with iespect to chemical composition, are: (1) Uric acid (red deposit) ; (2) urates of ammonia, soda, lime, etc. (brick-dust sediment) ; (3) phosphates of ammonia and magnesia, lime, etc.: (4) oxalate of lime; (5) carbonate of lime (chiefly in domestic animals) ; (6) cystin; (7) xanthic oxide (a very rare form, discovered by Dr. Marcet). Calculi are frequently found to be composed of numerous successive layers, each having a perfectly distinct chemical composi tion. Urates and phosphates in particular fre quently succeed each other, and form what is called an alternating calculus. When calculus has once fairly formed in the urinary passages, no absolute cure exists except the removal of it, if possible. from the body (see LITHOTOMY ; LITHOTRITY ; and NEPHROTOMY ) ; but in the stage of gravel, and still more in the earlier stages detected by careful examination of the urine, much may be done to check the tendency to this distressing and dangerous malady. The chief remedies consist in careful regulation of the diet and mode of living, together with the use of solvents adapted to the particular form of deposit found to he habitually present. Con sult Park, Surgery by American Authors (New York. 1901). See URINE.