According to Joslin, it must be remembered that similar reaction is obtained in the urine of individuals taking salicylates, antipyrin, cyanates, or acetates, but it is a simple process to differentiate between the color produced as a result of diacetic acid and that produced by the above-mentioned drugs. If the solution is boiled for two minutes, the color from diacetic acid will disappear, owing to the unstableness of that substance, while that from the drugs will remain unchanged. ~Test for Acetone.~--Pour 5 c.c. of urine to be tested into a test tube, add a crystal of sodium nitroprusside, acidify with glacial acetic acid, shake well, and then make alkaline with ammonium hydrate. The presence of acetone is indicated by a purple color. TESTS FOR ALBUMEN The heat test[113] is the simplest. This consists of first filtering the urine through filter paper, then pouring some of the clear urine into a test tube, holding the test tube in a flame so that only the upper layer boils, then adding a few drops of 2% solution of acetic acid and boiling again. If there is albumen present, a very faint, or a heavy cloudiness (precipitate of coagulated albumen) forms on boiling and persists or becomes heavier on the addition of a few drops of dilute acetic acid (2%) and boiling again. If a precipitate occurs at the first boiling, but clears up again entirely on adding acetic acid, it is not albumen but harmless phosphates or carbonates. HELLER'S TEST FOR ALBUMEN Into a test tube pour a few drops of nitric acid, filter the urine and allow a small quantity of it to trickle from a pipette down the side of a test tube until it comes in contact with the acid. If albumen is present a distinctly formed white ring is seen at the zone of contact. TEST FOR INDICAN This material is found in cases of obstinate constipation and in other intestinal disturbances where the passage of the food mass in the small intestines is delayed and the putrefactive bacteria exert their activities upon the unabsorbed protein. ~Test.~--Mix equal quantities of urine and fresh hydrochloric acid and add drop by drop fresh concentrated solution of chloride of lime (5 to 1,000). Indican is indicated by the appearance of a blue color. SUMMARY ~Urinalysis~ represents one of the most important means for determining the health of an individual, since it is the urine that shows those substances produced in the body as a result of the breaking down of the body tissues and protein foods. ~Composition of Normal Urine~ must be familiar to the nurse in order that she may recognize any change taking place in the urine of her patient which may indicate pathological conditions in the body. ~The Specific Gravity~ of urine is one of the points by means of which the presence of certain substances more or less abnormal in character is determined. ~Other Points~, such as color, odor, quantity, reaction, and chemical composition, likewise show any deviation from the normal in the individual.