APPENDIX 



183 



The finger is pricked, and the blood allowed to flow into the small 

 capillary pipette (fig. 65, a) until it is full. This is washed out by the 

 dropping tube b into a graduated flattened test-tube, c, with Hayeni's fluid.^ 

 The graduations of the tube are so adjusted that with normal blood con- 

 taining 5,000,000 colomed corpuscles per cubic millimetre, the light of a 

 small wax candle placed at a distance of 9 feet from the eye in a dark room 

 is just transmitted as a fine bright line when looked at through the tube held 

 edgeways between the fingers (d) and filled up to the 100 mark of the gradua- 

 tion. If the number of corpuscles is less than normal, less of the diluting 

 solution is reqviired for the light to be transmitted ; if above the normal, more 

 of the Hayem's fluid must be added. The tube is graduated, so as to indicate 

 in percentages the decrease or increase of corpuscles per cubic millimetre as 

 compared with the normal standard of 100 per cent. 



RSHOGLOBIFOMETEBS 



Gowers's Haemoglobinometer. — The apparatus consists of two glass tubes, 

 C and D of the same size. D contains glj-cerin jelly tinted with carmine to 

 a standard colour — viz., that of normal blood diluted 100 times with distilled 

 water. The finger is pricked and 20 cubic millimetres of blood are measured 

 out by the capillary pipette, B. This is blown out into the tube C, and diluted 



Fig. 66.— H«moglobiiiometer of Sir W. Gowers. 



with distilled water, added drop by drop from the pipette stopper of the 

 bottle, A, until the tint of the diluted blood reaches the standard colomr. The 

 tube C is graduated into 100 parts. If the tint of the diluted blood is the 

 same as the standard when the tube is filled up to the graduation 100, the 

 quantity of oxyhaemoglobin in the blood is normal. If it has to be diluted 



' Sodium sulphate 5 grammes, sodium chloride 1 grm., mercuric chloride 

 0-5 grm., distilled water 200 c.c. 



