Appendix /. On methods 295 



Put the apparatus in the water bath. 



After five minutes read the meniscus on each side 



Left Right Zero error iu p 



120 119-5 -5 



Close the taps ; after two minutes if the meniscus has not moved upset the ferri- 

 cyanide on one side with the precautions indicated above ; shake for one minute and 

 place in the bath for one minute ; read again 



Left Eight p 



93 146-5 53 -5 +-5 = 54 



Shake again for one minute and allow to stand for one minute ; read 



Left Right p 



91 148-5 57-5+ -5 = 58 



Shake again for one minute and allow to stand for one minute 



Left Right p 



91 148-5 57-5+ -5 = 58 



The value of p is now constant, had it not been so the operation of shaking, &c., 

 must have been continued. 



The volume of gas given off is p+A; = 57x3'03 = 171 cubic mm. or '171 c.c. 



This must be reduced for temperature and pressure and corrected according to 

 the calibration of the 1 c.c. pipette. Suppose the latter delivers "96 c.c., that the 

 temperature is 15C. and the pressure 755 mm. The oxygen capacity is then 



Repeat the operation on the other side of the apparatus. 



Correction of Haldane's standard haemoglobinometer. 



The importance of the above determination is great, owing to the fact that it is 

 the only practical way of ascertaining the correctness of a standard haemoglobino- 

 meter. 



Haldane's standard instrument is constructed so that 100 on the scale corresponds 

 to an oxygen capacity of '185 c.c. of oxygen per c.c. of blood. The reading of any 

 blood on Haldane's scale should therefore be 



The oxygen capacity as determined 



^185" 

 That given above should be 



If it is not so, as the result of careful determination the standard solution in the 

 haemoglobinometer is incorrect. 



