APPENDIX 



HJEMACYTOILETEES 



Gowers's Haemacytometer. — The enumeration of the blood corpuscles is 

 readily effected by the haemacj'tometer of Gowers. This instrument consists 

 of a glass slide (fig. 64, C), the centre of which is ruled into ^ millimetre 

 squares and surrounded by a glass rim J millimetre thick. It is provided 

 with measuring pipettes (A and B), a vessel (D) for mixing the blood with a 

 saline solution (sulphate of soda of specific gravity 1015), a glass stirrer (E), 

 and a guarded needle (F). 



FiQ. 64. — Hsmacytometer of Sir W. Gowers. 



Nine hundred and ninety -five cubic millimetres of the saline solution are 

 measured out by means of A, and then placed in the mixing jar ; 5 cubic 

 millimetres of blood are then drawn from a puncture in the finger by means 

 of the pipette B, and blown into the solution. The two fluids are well 

 mixed by the stirrer, and a smaU drop of this diluted mixture placed in the 



