IV 



THE BLOOD: FORMED CONSTITUENTS 



113 



light remaining after the luminous rays have traversed the colouring matter 

 of the blood, the negative logarithm that represents the extinction co-efficient 

 can be calculated, and this must be multiplied first by the constant of the 

 spectral tone obtained, and then 

 by the degree of dilution of the 

 blood. Thus it is calculated how 

 many grams of haemoglobin are 

 contained in 1 c.c. of blood. 



Practical Example. Let the 

 blood under examination have 

 been diluted 200 times, and the 

 first spectral region be that in 

 which the constant is "001 330, 

 the intensity of the remaining 

 light will be found to be 0'255 ; 

 to calculate the amount of oxy- 

 haemoglobiii contained in 1 c.c. 

 of the blood, multiply 0'001330 

 by 200, and then by the negative 

 logarithm of 0'255, i.e. by 0'5935. 

 In this case the oxyhaemoglobin 

 of 1 c.c. of blood will be equal to 

 0'1578 grm. 



VIII. The White Blood 



eS Or LeUCOCyteS are FIG. 39. A, Absorption-chamber with parallel faces; 

 pnmrilprp pplk r>nn A Schultz' cube, made of glass 1 c.c. in depth, in- 



(.Ompiete CeilS, COU- traduced into the chamber. 



sisting of naked granular 



protoplasm, with one/ or more nuclei, which are not easy to dis- 



> 



F IG . 40. Different kinds of human leucocytes examined either in the fresh state, or after fixation 

 with various reagents, magnification about 1000 diameters (partly from Kanthack and Hardy), 

 a, a', fe, Fresh leucocytes of three different sizes, in the resting state ; c, the same in amoeboid 

 state ; d, polynuclear acidophile leucocytes with large (d 1 ) and fine (d") granulation ; e, e', c"., 

 hyaline leucocytes, destitute of granules; /, lymphocytes; g, leucocytes- with basophile 

 granulation. 



tinguish in the fresh state, but may become very conspicuous on 

 adding a drop of acetic acid to the microscopic preparation. 

 VOL. I I 



