EXAMINATION OF THE BLOOD. 141 



block and then to tie a piece of string round it and dip 

 it quickly into melted paraffin (a candle will do) and 

 allow the coating to set ; the dipping is to be repeated 

 several times, and the specimen (string and all) may 

 then be packed without further precautions. In any 

 case it must reach the laboratory as soon as possible. 



Where cultural examinations are not required small 

 portions of the organs should be placed in a suitable 

 hardening fluid as soon as possible. 



Other solid organs are treated in the same way. 

 Fluids (pus, the contents of cysts, pericardial or other 

 fluid, &c.) should be collected in pipettes in the manner 

 adopted for the heart-blood. 



EXAMINATION OF THE BLOOD. 



A clinically complete examination of the blood in- 

 cludes : 



1. A determination of the number of red corpuscles 

 present per cubic millimetre. (Normal numbers being 

 5,000,000 in the adult male and about 4,500,000 in the 

 female) . 



2. A determination of the number of leucocytes pre- 

 sent per cubic millimetre (the normal is between 4,000 

 and 10,000). 



3. A determination of the amount of haemoglobin 

 expressed as a percentage of the normal amount. 



4. An examination of stained specimens to ascertain 

 the presence or absence of abnormal corpuscles, and the 

 relative proportions of the leucocytes present. 



In addition to these it is sometimes necessary to 

 make : 



5. A determination of the presence or absence of 

 parasites. 



