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A MANUAL OF PHYSIOLOGY 



Owing to the great stability of the compound, the haemoglobin can 

 no longer be oxidized in the lungs, and death may take place from 

 asphyxia. It is, however, gradually broken up, and therefore arti- 

 ficial respiration may be of use in such cases. Inhalation of oxygen 

 and especially transfusion of blood are also of great value. 



Methfemoglobin is a derivative of oxy haemoglobin which can be 

 formed from it in various ways, e.g., by the addition of ferricyanide 



/\cid Haematin, 

 Alkaline Hacmatin 

 Reduced Hb. 



FIG. 9. DIAGRAM TO SHOW^ THE CHIEF CHARACTERISTICS BY WHICH HAEMO- 

 GLOBIN AND SOME OF ITS DERIVATIVES MAY BE RECOGNIZED SPECTROSCOPI- 



CALLY. THE POSITION OF THE MIDDLE OF EACH BAND is INDICATED 



ROUGHLY BY A VERTICAL LlNE. 



of potassium or nitrite of amyl (Gamgee), by electrolysis (in the 

 neighbourhood of the anode), or by the action of the oxidizing fer- 

 ment ' echidnase ' in the poison of the viper (Phisalix) . It very 

 often appears in an oxyhaemoglobin solution which is exposed to 

 the air. It has been found in the urine in cases of haemoglobinuria, 

 in the fluid of ovarian cysts, and in haematoceles. The strongest 

 band in its spectrum is in the red, between C and D, but nearer C, 

 nearly in the same position as the band of acid-haematin . Reducing 



FIG. 10. DIAGRAM TO ILLUSTRATE THE DISTRIBUTION OF THE BLOOD IN THE 

 VARIOUS ORGANS OF A RABBIT (AFTER RANKE'S MEASUREMENTS). 



The numbers are; percentages of the total blood. 



agents, such as ammonium sulphide, change methaemoglobin first 

 into oxyhaemoglobin and then into reduced haemoglobin. It has by 

 some been regarded as a more highly oxidized haemoglobin than 

 oxyhaemoglobin. Rebutting evidence has, however, been offered to 

 the effect that the same quantity of oxygen is required to saturate 

 both pigments, and this evidence appears to be sound. The differ- 

 ence lies rather in the manner in which the oxygen is united to the 



