22 5 



the haemoglobin. The isotonic point of human blood 

 is about 0*41 per cent, salt solution. 



To DETERMINE THE ISOTONIC POINT 



1. Measure out one c.c. of each salt solution 

 of descending strengths, 0*43 per cent., 0*41 per cent., 

 0*39 per cent., etc., into four small test tubes and 

 one c.c. of water into a fifth tube. 



2. Add to each the amount of blood (or the blood 

 may be washed free from serum by centrifugalizing 

 and used as an emulsion of known strength in salt 

 solution) contained in two divisions of the stem of a 

 Thoma-Zeiss pipette (the whole stem contains ten 

 divisions). 



3. Allow to stand for some time. Some of the 

 solutions will have haemoglobin in solution. 



In malaria, the resistance of the blood is lowered, 

 thus, whereas in a control normal blood a 0*41 per cent, 

 salt solution gave no haemolysis ; in the case of two 

 malaria patients, the haemolysis was well marked. 



In blackwater fever, on the contrary, a raised 

 resistance of the blood may be found. 



THE URINE 



It is especially in blackwater that we still require 

 complete analyses of the urine, and more especially 

 in those who are constantly subject to malarial attacks 

 and are at the same time taking quinine. It is possible 

 that such analyses might give us indications which 

 would enable us to avert the danger of an attack of 

 blackwater fever and to determine when quinine should 

 not be given. 



Albuminuria. The occurrence of albuminuria in 

 malaria varies according to the particular country ; 



