188 EXCRETION. 



It is somewhat difficult to measure the exact temperature 

 of the urine at the moment of its emission. In some recent 

 observations on this subject, by Dr. Byasson, in which a very 

 delicate thermometer was used, and extraordinary care was 

 taken to prevent any change in temperature before the esti- 

 mate was made, the temperature, under physiological condi- 

 tions, varied but a small fraction of a degree from 100 Fahr. 1 

 It is important to know the normal temperature of the urine, 

 as it is liable to vary very considerably in certain diseases. 



Quantity, Specific Gravity, and Reaction of the Urine. 

 In estimating the total quantity of urine discharged in the 

 twenty-four hours, it is important to take into consideration 

 the specific gravity, as an indication of the amount of solid 

 matter excreted by the kidneys. We have already alluded 

 to some of the variations in quantity constantly occurring in 

 health, as depending upon the proportion of water but the 

 amount of solid matters excreted is usually more nearly uni- 

 form. It must also be taken into account that differences 

 in climate, habits of life, etc., in different countries, have an 

 important influence upon the daily quantity of urine. Dr. 

 Parkes has collected the results of twenty-six series of obser- 

 vations made in America, England, France, and Germany, 

 and finds the average daily quantity of urine in healthy male 

 adults, between twenty and forty years of age, to be fifty- 

 two and a half fluidounces, the average quantity per hour 

 being two and one-tenth fluidounces. The extremes were 

 thirty-five and eighty-one ounces. 3 



In attempting to decide the question whether a certain 

 quantity of urine passed be abnormal or within the limits of 

 health, it is important to recognize, if possible, certain limits 

 of physiological variation. Becquerel states that the varia- 

 tions in the proportion of water in the urine likely to occur 



1 BYASSON, Essai sur la relation qui exisle d V etat physiologiqw entre Vactivite 

 cerebrate et la composition des urines, Paris, 1868, p. 42, table. 



2 PARKES, The Composition of tJie Urine, London, 1860, p. 6. 



