1292 



OX Y-H,EM( )GLOBIN. 



water at 0° containing 25 p.c. of alcohol, and may be dried in 

 vacuo over sulphuric acid at 0°, and are now fairly stable. 



The crystals obtained from the haemoglobin of various 

 animals differ in their crystalline form. The following figure 

 shews some of the most typical forms. 



Numerous analyses of oxy-haemoglobin have been made, but 

 these while they tell us at most that it consists of oxygen, 

 hydrogen, nitrogen, and carbon together with iron as a charac- 

 teristic constituent and some sulphur, and seem to indicate 

 that it differs in composition as obtained from different animals, 

 do not as yet enable us to assign with any certainty a definite 

 formula to its composition. It is however certain that its 

 molecular weight is enormously great (13,000 — 11,000). 



Fig. 230. Crystals of Oxt-h.emoglobin. (After Funke.) 

 a. Squirrel, b. Guinea-pig, c. Cat, or Dog, d. Man, e. Hamster. 



The spectroscopic appearances of solutions of oxy-ha3mo- 

 globin have been already sufficiently described and figured 

 (§ 276), but in addition to the bands there figured, it shews 

 also a band in the extreme violet between Gr and H, whose 

 centre corresponds to W. L. 414. 



There appears to be a consensus of opinion that hsemoglobin, 

 and more particularly oxy -haemoglobin, possesses to a slight 

 degree the properties of an acid. This view appears to be based 

 on the following facts. Oxy-hsemoglobin is extraordinarily 

 soluble in alkalis and in this solution appears to be more stable 

 than ordinarily. It is further stated that it has a feeble power 

 of facilitating the evolution of carbon-dioxide from dilute solu- 

 tions of sodium carbonate. It is hence often supposed that in 

 the red blood-corpuscles the haemoglobin is united to the alkalis 

 of which their stroma partially consists. If the above views 



