118 



CHEMICAL PHYSIOLOGY. 



Example. Suppose the patient passes 8550 cc. of urine, then 

 as 1*8 cc. of urine reduced all the cupric oxide in the 10 cc. of 

 Fehling's solution, it must contain -05 gramme sugar; hence 



1-8 : 8550 : : -05 .-. 855 1 * ' 5 = 237'5 grammes of sugar passed 

 in twenty-four hours. 



3. Picro-Saccharimeter of G. Johnson. 



Solutions Required. 



(1.) A solution of ferric acetate equal to that yielded by a solu- 

 tion of sugar containing J grain per fluid ounce. 

 (2.) Saturated solution of picric acid. 

 (3.) Liquor Potassse B.P.) 



(a.) Measure 1 fluid drachm of urine into- 

 the boiling tube, add 30 minims of liquor 

 potassse and 80 minims of the saturated 

 solution of picric acid. Make up to the 

 4-drachm mark 011 the tube with distilled 

 water. Boil for one minute. 



(b.) Dip the tube in cold water to cool it. 

 The volume must be exactly 4 drachms. 

 If it is less, add water ; if more, evaporate 

 it. If the colour of the boiled liquid is- 

 the same as that of the ferric acetate J 

 grain standard, or paler, the urine con- 

 tains 1 grain of sugar per fluid ounce, or 

 less. 



(c.) Should the colour be darker than 

 the standard, place some of the boiled 

 liquid into the graduated stoppered tube 

 (Fig. 30) to fill 10 divisions of the scale, 

 while the stoppered tube affixed to the 

 former is filled with the SS. of ferric ace- 

 tate. Fill up the graduated tube with 

 distilled water until the dark red liquid 

 has the same colour as that of the SS. 

 These tints are best compared in the flat- 

 bottomed tubes supplied with the ap- 

 paratus. 



(d.) Read off the level of the fluid in the- 



Fig. 30. Picro- 

 saccharimeter. 



