When the physiological mechanism is working perfectly, says Porter, the urine is free from indican (a substance formed from indol, which has its source in intestinal protein putrefaction) . If the urine is free from indican there is no putrefaction in the intestine? If there is over production of uric acid (a reddish yellow crystal-line acid, as obtained from urine), it may not be of any immediate significance; but unless the cause is found and corrected any excess may indicate grave structural changes in vital organs.
In testing for indican, it is necessary to understand the significance of the different shades of color obtained. In simple indicanuria, (showing the presence of indican without complications) the test reaction gives a clear indigo blue. When more or less toxic material is produced the color is a decided purple. The darker the color the more serious the toxemia (from putrefaction). In the type of red indicanuria the indican is not precipitated, as in the case of the blue forms, but the result is very pronounced reddish coloration of the urine in the tube above the surface of the chloroform (see figure), while the latter remains colorless. Other color reactions are a greenish coloration of the chloroform, indicating the presence of bile?
When the assimilation is perfect the indican test in-variably shows a sharp line of demarcation between the chloroform and the urine. If assimilation is impaired a more or less opaque disc forms at the junction of the urine and chloroform, varying in thickness from 1/8 to 1 inch. The location of the disc above or below the line has some significance.
Obermayer’s test for indican, recommended by Green: Put in a test tube 1 cubic centimeter Obermayer’s reagent (15 drops) and an equal part urine to be tested, add 2 cubic centimeters of chloroform and thoroughly shake. A blue color will develop if indican be present.
None of the indications mentioned are in themselves of serious import. They are given as showing some of the early manifestations of imperfect assimilation, which, in the classes of cases we are considering, arise from improper diet and overeating.
The examination of the urine for uric acid (a significant end product of protein decomposition) and albumen, another protein product (frequently indicative of kidney inefficiency), should be entrusted to a physician who specializes in such examinations or to a physiological chemist. Traces of these substances may be present in the urine from natural causes and the presence of sugar, especially after a full meal, may also be sporadic and not indicative of diabetic changes already accomplished.
Urea, says Emerson, is the nitrogenous body of the urine present in the largest amount. The output of urea has been used as a test of digestion. A meal containing an excess of nitrogen may have included, for illustration, 500 grams of meat, 8 eggs and 200 grams of bread. During the same or the following day at least 50 grams of urea should be excreted. A normal person on an average diet is supposed to excrete 20 to 40 grams of urea each 24 hours. Why is there any great excess of urea at all in the urine? Urea is the chief nitrogenous ash of nitrogen food. Another opinion is that urea represents the excess of nitrogenous (animal food) in-take of our food. Still another, that some of the protein food broken down is not resynthesized or built up again into a form to be used by the body.
There is a simple and effective method of ascertaining if the kidneys are functioning properly. The density of urine, as shown by its specific gravity, is practically never the same in successive tests. This means that the more concentrated the fluid the higher a buoyant object will float in it. A urinometer looks much like a thermometer without the frame. It is buoyant and weighted with quicksilver. The lower it sinks in a fluid the lower the
specific gravity of the fluid as indicated by a scale on the stem of the instrument. If a urinometer is dropped into urine each time it is voided during the day and the specific gravity noted these notations at the end of the day should show marked variations. Such a result indicates that the kidneys are active and functioning properly. If, on the contrary, there is slight or no variation it indicates that the kidneys are exhibiting incapacity. With copious water drinking the color be-comes light while the specific gravity may drop in health to as low as 2 (according to Starling) which means but 2 points denser than water, and is written 1.002. Or in health, with heavy eating, it may rise to 1.015, or even to 1.040 on occasion. In a few diseases, such as some forms of Bright’s disease, the milder form of diabetes (diabetes insipidus), dropsy and heart disease, low specific gravity is one of the persistent symptoms.
A limpid, light-colored urine in sufflcient quantity and of natural color, indicative of health, free water drinking and moderate dietary, quickly gives way to a dense, dark colored, aciduous and ill-smelling fluid, as soon as the digestive organs are overloaded with such food as meat and eggs and denied an adequate supply of drinking water. Here is a plain danger sign that few notice and fewer still heed. Tested with the urinometer such urine registers a high specific gravity.
Apoplexy, aneurism (localized dilation of a weakened arterial wall) angina pectoris (breast pang), sudden death from failure of power in a fatty heartall are the outcome of the blood being loaded with nitrogenous waste. If these protein poisons had been removed all the rest could have been avoided. The bulk of the urine in these cases is commonly small, dark in color, yet of high specific gravity, well charged with urates of sodium, ammonium, potassium, calcium and magnesium. An excess of uric acid in the urine is called lithuria. It is precipitated by cold as if it were brick dust. Usually, too, the patient gets up at night to pass water. Sometimes a large bulk of limpid, light-colored urine alternates with this condition of scanty urine. In women especially there is breathlessness and palpitation in effort. Such a condition requires a sharply restricted diet involving a great deal of self-denial, but the result is worth all the pains. As to meat it should be confined to a little fowl or fish, plenty of vegetables and a mixed diet. This caution is particularly applicable where there is a tendency to a full habit or high blood pressure. The condition of the intestinal tract requires constant attention. A good drink in such circumstances is citrate of potassium as often as twice a day, well diluted.