72 The Microscope. 



they meet in the lungs, and by the heart's action this vital gas is 

 again carried forward in its endless path of circulation. It has been 

 fully demonstrated by experiments that so long as the haemato- 

 ciystalline remains normally the same, in quality as well as quantity, 

 the supply of oxygen to the economy is subject to relatively small 

 oscillations, and with the increase or decrease of this wonderful 

 substance, or w^ith any alteration of its integrity, rises or falls the 

 degree of vitality in an individual's life. That it is beyond any 

 question the haemo-crystalline, and not any other substance of the 

 blood, which enters into and sustains the vital exchanges between 

 oxygen and carbonic acid has been fully proved by spectrum analysis. 



Haemato-crystalline in solution is able to aborb oxygen, as well 

 as carbonic acid, with the greatest avidity. It can exist, like the 

 blood itself, in a double state of oxidation, corresponding to arterial 

 and venous. It can be oxidized and deoxidized at pleasure by 

 chemical, and also by mechanical means. It presents the same 

 . absorption bands as blood does when examined spectroscopically, and 

 these blood bands are also found in the exact part of the spectrum; 

 it enters into precisely the same combinations with the irrespirable 

 gases, and all and every optic appearance which blood presents 

 when acted upon by chemical agents, are also faithfully reproduced 

 when the same agents act upon a solution of haemato-crystalline. 



As to the approximate quantity of this haemato-crystalline, 

 experiments made show, that in the total blood mass, nine to twelve 

 per cent, is contained in the moist corpuscles; freed fi'om serum, it 

 rises from eighteen to twenty per cent. 



THE HAEMATO-CRYSTALLINE AS SUCH IS NOT FOUND IN THE HUMAN BLOOD. 



Considerations that would lead us too far from our present 

 subject, and require far more space than can reasonably be spared 

 for this paper, forbid a more detailed account of its normal state in 

 the blood. According to the best authorities, it is there joined to an 

 alkali. When we reflect that the blood is an alkaline fluid, we will 

 at once assent to this proposition, especially so, when experience 

 shows us that this substance can only be obtained in crystalline 

 form, when the blood loses its alkalinity and changes to a state of 

 acidity. Thus the prolonged passage of a current of oxygen gas 

 through a blood-solution is one of the means to obtain the artificial 

 crystals. 



Preyer thinks that it is joined to potassa in the blood, on 



