4 S8 PRACTICAL ORGANIC AND BIO-CHEMISTRY 



(4) Hoppe-Seylers Method. 



*i c.c. of blood is diluted with a known small amount of water and 

 compared against a standard solution of oxyhaemoglobin prepared from the 

 pure crystalline compound. The unknown is diluted until the colours match. 

 The amount of dilution is noted. The dilution of the standard is known ; 

 the two colours are proportional to their dilutions and the haemoglobin value 

 can thus be calculated. 



(5) Gowers' Method. 



Gowers, instead of using a haemoglobin standard as in Hoppe- 

 Seyler's method, used a standard of glycerin jelly stained with 

 picrocarmine of such a colour that it corresponded to normal blood 

 diluted IOO times with water. It is contained in a small sealed tube. 

 The comparison is made in a similar tube with 20 cmm. of blood which 

 is diluted with water until it has the same tint. This tube is graduated 

 in percentages so that the value is directly observed. The method 

 of estimation is carried out in the same way as is described under 

 Haldane's method. 



(6) Haldanes Method. 



Haldane has modified Gowers' methad by using a standard solu- 

 tion of ox blood or sheep's blood saturated with carbon monoxide in 

 the place of the carmine-tinted glycerin jelly. The standard is a 

 I per cent solution of defibrinated ox blood saturated with coal gas. 

 It has an oxygen capacity, determined by Haldane's ferricyanide 

 method, of 18*5 per cent. ; the carbon monoxide capacity is the same. 

 Since I gm. of haemoglobin combines with 1-34 c.c. of oxygen at 

 N.T.P., it corresponds to 13-8 per cent, of haemoglobin. This is the 

 same as that of adult males. Women's blood averages 1 1 per cent., 

 children's blood 13 per cent. In determining the percentage of 

 haemoglobin in these cases \ should be added for women's blood and 

 ^ for children's. The standard, kept in the dark, will remain unaltered 

 for years. 



The apparatus necessary for the estimation is the standard tube 



(D), a companion tube 

 graduated in percent- 

 ages (C), a lancet for 

 pricking the finger (F), 

 a pipette to measure 

 20 cmm. of blood (B), 

 a tube to pass carbon 

 monoxide or coal gas 

 into the vessel and a 

 bottle of distilled water 

 saturated with coal gas 

 with a drop pipette for 

 gradually diluting the 

 blood (A). The items 

 are shown in Fig. 61. 



FIG. 61, 



