66 



PRACTICAL PHYSIOLOGY. 



[VII. 



(ft.) Spread a sheet of white paper on a table in a good light opposite a 

 window, and on it place two haematinometers side by side (fig. 31, D). See 

 that they are water-tight. If not, anoint the edges of the glass plates with 

 vaseline to make them water-tight. 



(c.) Take 10 cc. of the standard solution of haemoglobin and dilute it with 

 50 cc. of water, and place it in one of the hsematinometers. 



(d.} Weigh 5 grams of the blood to be investigated, and dilute it with 

 water exactly to 100 cc. 



(e.} Place 10 cc. of this deeper tinted blood (d.) into the second hsematino- 

 meter. 



(/.) Fill an accurately graduated burette with distilled water, place it over 

 the second haematinometer (c. ), and dilute the blood in it until it has precisely 

 the same tint as the standard solution in the other haematinometer. Note the 

 amount of water added. The two solutions must now contain the same 

 amount of haemoglobin. 



Example (Hoppe-Keyler}. 20.186 grams of defibrinated blood were diluted 

 with water to 400 cc. To the 10 cc. of this placed in a haenlatinometer, 38 



FIG. 39. Zeiss's Microspectroscope after AT be. Fie. 40 Adjustable Slit in Fig. 39, A. 



cc. of water had to be added to obtain the same tint as that of the standard 

 solution, so that the volume of water which would require to be added to 

 dilute the whole 400 cc. would be 1520 cc., thus 



10 : 400 : : 38 : x 

 x = 1520 cc. 



By adding 1520 cc. of distilled, water to the 400 cc. of blood solution, we gel 

 1920 cc. of the same tint or degree of dilution as the standard solution. 



The standard solution on analysis was found to contain 0.145 grams of 

 haemoglobin in 100 cc., so that the total amount of haemoglobin in the diluted 

 blood is found, thus 



100 : 1920 : : 0.145 ' x 

 x = 2. 784 grams. 



