382 APPENDIX. 



(2) Dissolve 320 grains of the double tartrate of sodium 

 and potassium, in warm -water, add a little carbolic 

 acid to prevent the growth of fungi, fill up with 

 water to exactly a litre and filter. 



(3) Dissolve 150 grams of caustic sodium hydrate in 

 water dilute to a litre with water. If the fluid is 

 cloudy, filter through asbestos, or let stand and 

 decant the clear fluid. 



From the above, Fehling's fluid should be made at the 

 time it is required for use. It will not keep. To 

 make it, equal quantities of (1), (2) and (3) are 

 mixed together. The cupric sulphate should be 

 shaken up and a given quantity, say 100 c.o., 

 accurately measured, to this, 100 c.c. of (2) is added, 

 and then (3) to. make up the volume to exactly 

 300 c.c. From 10 c.c. of this mixture, the cupric 

 salt is reduced by '05 gram of dextrose. 



Stokes' flnid. 



This should be made afresh when required ; it consists 

 of ' a solution of ' ferrous sulphate, to which ammonia 

 has been added after the previous addition of 

 suflElcient tartaric acid to prevent precipitation. 

 An excess of tartaric acid is not of consequence ; 

 roughly speaking, three parts by weight may be 

 added to two parts of ferrous sulphate. 



Majoe Arterial Scheme. 



This (see Fig. 8) is a modification of Weber's original 

 scheme of the circulation. It is not intended to 

 imitate the details of the circulation of the blood, 

 but simply to illustrate the points to which attention 

 is called in Lesson xiii. It can without much 



