496 OF SECRETION AND EXCRETION. 



however, may be due to the simple augmentation of the bulk of the blood, 

 and especially of its solids. But, again, any cause which produces conges- 

 tion of the vessels of the kidney, favors the passage of the normal albumen 

 of the blood into the urine j 1 and thus we see how albuminous urine may be 

 produced by the repulsion of blood from the cutaneous surface to the kidney, 

 or by the determining influence of cautharides or other irritant diuretics, or 

 by any obstruction to the return of blood from the capillary plexus by the 

 renal veins. 2 



406. The nature and purposes of the Urinary secretion, and the alterations 

 which it is liable to undergo in various conditions of the system, are much 

 better understood than are those of the Bile : this is owing, in great part, to 

 the two circumstances, that it may be readily collected in a state of purity, 

 and that its ingredients are of such a nature as to be easily and definitely 

 separated from each other by simple chemical means. There can be no doubt 

 that the chief purpose of this excretion, is to remove from the system the 

 effete azotized matters, which the blood takes up in the course of its circula- 

 tion, or which may have been produced by changes occurring in itself. This 

 is evident from the large proportion of Nitrogen in the solid matter dissolved 

 in the urine ; and from the crystalline form presented by much of this solid 

 matter when separated, a form which indicates that its state of combina- 

 tion is such as to prevent it from conducing to the nutrition of the system. 

 The injurious effects of the retention of the components of the Urinary secre- 

 tion in the Blood, are fully demonstrated by the results of its cessation ; 

 whether this be made to take place experimentally (as by tying the renal 

 artery), or be the consequence of a disordered condition of the kidney. The 

 symptoms of Urcemia (as this condition has been appropriately termed) are 

 altogether such as indicate the action of a specific poison upon the Nervous 

 system ; affecting either the Brain or the Spinal Cord, separately, or both 

 together. In the first form, a state of stupor comes on rather suddenly, out 

 of which the patient is with difficulty aroused ; and this gradually deepens 

 into complete coma, with fixed pupils and stertorous breathing, just as in 

 ordinary kinds of narcotic poisoning. In the second form, convulsions of an 

 epileptic character, frequently affecting the whole muscular system, suddenly 

 occur; but there is no loss of consciousness. In the third form, coma and 

 convulsions are combined. These effects have been attributed by Frerichs 



1 See Robinson in Med -Chir. Transact., vol. xxvi, p. 51. 



8 Magendie, indeed, found that the mere injection of about a pint of wator into the 

 veins of a large dog was sufficient to cause the urine quickly to become albuminous, 

 the effect remaining for 10 or 12 hours (Bernard, .09011*, 1859, vol. ii, p. 139). Over- 

 beck (Sitzungsbericht d. k. Akad. d. Wiss. zu Wien, 1863, p. 189) has also made the 

 curious observation, that compression of the renal arteries, whilst it rapidly dimin- 

 ishes the quantity of urine and of urea secreted, also occasions the discharge of albu- 

 men in the urine; though if at the same time a ligature be applied to the ureters, 

 the appearance of albumen is completely prevented. Albuminous urine has been 

 observed in certain forms of heart disease (Rayer), and after certain lesions of the 

 nervous system, as intracranial section of the fifth pair of nerves (Longet, Physiologic, 

 p. 952), and section of the cerebral peduncles (Schiff) ; also in scarlet fever, measles, 

 small-pox, erysipelas, pytemia, typhus, typhoid, rheumatic and malarial fevers, 

 cholera, purpura, scurvy, diabetes, syphilis, certain forms of pneumonia, pregnancy, 

 post-parturient conditions, go'it, chronic alcoholism, and dyspepsia from excessive 

 eating. See G. Johnson, British Med. Journal, January llth, 1873. It has been 

 shown by Brown-Sequard, Schiff, and other experimenters, and especially by Ollivier 

 (Archives (lenerales de Med., 1874, February) that both puncture of the floor of the 

 fourth ventricle, and haemorrhage into the substance of the hemispheres, is attended 

 with great congestion of the kidneys, and albuminuria, but whether, as Schiff thinks, 

 this is due to paralysis of the vaso-motor nerves, or, as Brown-Sequard thinks, from 

 spasm of the veins, or of the veins and arteries, leading to engorgement and rup- 

 ture of the capillaries, cannot at present be stated with certainty. 



