TESTS FOR ALBUMIN IN URINE. 409 



or it may be persistent, as in cases of congestion following heart disease, emphysema, chronic 

 pleuritic effusions, infiltrations of the lungs, and after compression of the chest, causing conges- 

 tion in the pulmonary circuit, which extends even into the renal veins, &c. 3. After section 

 or paralysis of the vaso-motor nerves of the kidneys, which causes great congestion of these 

 organs. The albuminuria, which accompanies intense and long-continued abdominal pain, is 

 brought about owing to a reflex paralysis of the renal vessels. 4. After violent muscular 

 exercise. [Senator found that forced marches in young recruits were very frequently followed 

 by the appearance of albumin in the urine, which persisted for several days.] Convulsive dis- 

 orders, e.g., epilepsy, the spasms of dyspnoea after strychnin poisoning, in shock of the brain, 

 apoplexy, spinal paralysis, and violent emotions ; the excessive use of morphia, which perhaps 

 acts on the vaso-motor centres. 5. It may accompany many acute febrile diseases, e.g., the 

 exanthemata (scarlet fever), typhus, pneumonia, and pyaemia. In these cases, it may be due to 

 the increase of temperature paralysing the vessels, but more probably the secretory apparatus of 

 the kidney is so changed {e.g., cloudy swelling of the renal epithelium) that the albumin can 

 pass through the renal membrane. 6. Certain degenerations and inflammations of the kidneys 

 at several of their stages. 7. Inflammation or suppuration in the ureter or urinary passages. 

 8. Certain chemical substances which irritate the renal parenchyma, e.g., cantharides, carbolic 

 acid. 9. The complete withdrawal of common salt from the food. The albumin disappears 

 when the common salt is given again. 10. The epithelium may be in such a condition that it 

 cannot retain the albumin within the vessels, due to imperfect nourishment and functional weak- 

 ness of the excretory elements. This includes the albuminuria of ischfemia, and that after 

 haemorrhage, in anaemia, scorbutus, icterus, diabetes. [Grainger Stewart finds that albuminuria 

 is more common among presumably healthy people than was formerly supposed.] 



[Besides being derived from the secreting parenchyma of the kidney, albumin may be 

 present owing to admixture with the secretions from any part of the urinary tract, including 

 the vagina and uterus in the female. In some cases the transudation of albumin is favoured by 

 changes in the capillary walls, the albumin being forced through by the intravascular pressure. 

 Sometimes albuminuria occurs during the course of severe typhoid fever, and in acute fevers 

 generally, where the temperature is persistently above 40 C. (104 F.). The high temperature 

 alters the filtering membrane and permits the filtration of albumin.] 



[Physiological Albuminuria. This term has been applied to that condition of the urine, 

 where traces of albumin are found in individuals apparently in perfect health. Johnson and 

 Pavy cite such cases, while Posner asserts that all urine even healthy urine contains traces 

 of proteids, whose presence is ascertained after concentrating the urine. It is safe to assume 

 that normal urine should give no reaction with the usual tests for albumin. Posner precipi- 

 tated the urine with alcohol, washed the precipitate, dissolved it in acetic acid, and tested it 

 with the ferrocyanide test for albumin. He finds that minute traces of proteid are detected by 

 the following modification of the biuret test : Make the urine alkaline, and by the "contact 

 method" bring a layer of very dilute cupric sulphate over it; when the two fluids touch, a 

 reddish-violet ring is obtained.] 



The tests for albumin in urine depend upon the facts that it is coagulated by 

 heat in neutral or acid solutions, and it is precipitated by various reagents. 



[(1) Heller's Test. Place 10 c.c. of the urine in a test-glass, and pour in pure colourless 

 HNO3 so as to run down the side of the glass, forming a layer beneath the urine. A white 

 zone of coagulated albumin indicates the presence of albumin. In this test it is important to 

 wait a certain time for the development of the reaction. In urines of high specific gravity, a 

 haziness due to acid urates may be formed above where the two fluids meet, but its upper edge 

 is not circumscribed. The acid decomposes the neutral urates and forms a more insoluble acid 

 salt. This cloud of acid urates is readily dissolved by heat, while the albumin is not ; the 

 latter is always a sharply defined zone between the two fluids. In very concentrated urine 

 (rare), nitric acid may gradually precipitate crystalline urea nitrate. In patients taking 

 copaiba, nitric acid, by acting on the resin, causes a slight milkiness.] 



[(2) Boiling and Nitric Acid. Place 10 c.c. of urine in a test-tube and boil. If albumin be 

 present in small quantity, a faint haziness, which may be detected in a proper light, will be 

 produced. Add 10 to 12 drops of HN0 3 . If the turbidity disappears it is due to phosphates, 

 while if any remains it is due to albumin. If albumin be present in large quantity, a copious 

 whitish coagnlum is obtained. Precautions. (a) In all 'cases, if the urine be turbid, filter it 

 before applying any test, (b) How to boil. Boil the upper strata of the liquid, and take care, 

 if any coagulum be formed, that it does not adhere to the side of the tube, else the tube is 

 liable to break, (c) In performing this test with a neutral solution, note when the precipitate 

 falls, for albumin is precipitated about 70 C, phosphates not till about the boiling point, (d) 

 Amount of Acid. If too little (2 or 3 drops) HN0 3 be added, or too much (30 or 40 drops), we 

 may fail to detect albumin, although it is present.] 



(3) Ferrocyanide Test. By the addition of acetic acid and potassium ferrocyanide. [If 

 albumin be present, a white flocculent precipitate separates in the cold. Dr Pavy has intro- 

 duced pellets, consisting of a mixture of citric acid and sodic ferrocyanide. All that is required 



