1901] MICROSCOPICAL JOURNAL. 139 
especially the carbonates of soda, which are dissolved in 
the plasma. 
The specific gravity of human blood in the adult male 
may vary from 1,041, to1,067. The number of red blood 
cells is about 5,000,000 to the cubic millimeter of blood 
in a healthy adult male, and about 4,500,000 in the healthy 
female. If this number is exceeded which is very rare, 
the condition is called Polycythemia ;if decreased it is 
termed, Oligocythemia. Oneof the most marked instan- 
ces of the former which occurs, is the very extraordinary 
increase of red cells which is often met with in cases of 
congenital cardiac disease in children, amounting to as 
many as 8,000,000 to the cubic millimeter. A similar in- 
crease is seen in Phosphorous poisoning. Beside the or- 
dinary red blood cells, we find in health small red cells sup- 
posed to be immature red cells, and called microcytes, 
while we may at times find very large red cells or Mega- 
locytes. Not only may the red blood cells change but the 
quantity of their hamoglobin may also vary. Normal 
blood should contain 100 per cent, although we may have 
perfect health with the amount estimated at 85 per cent. 
This decrease is termed Oligochromaemia. In disease we 
find more or less marked alternation in the red cells them- 
selves and in their coloring matter. The microcytes and 
the megalocytes already mentioned may become greatly 
increased in number. The red cells when they become de- 
formed are termed Poikilocytes. Some red cells, which 
unlike ordinary red cells possess a nucleus and are capa- 
ble of amoeboid movement are usually given the very con- 
fusing name of Normo-blasts. Other cells have been 
found that contained pigment, or are vacuolized, or again 
so dim in appearance that they are called shadow corpus- 
cles. The proportion of the white to the red cells in health 
is about 1 to 500, but a very great variation may occur. 
Thus after meals the white corpusclesare al ways increased 
so that the proportion may be 1 to 150. On the other 
