EXAMINATION OF THE BLOOD. I41I 
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. 
