IQ2 TRANSFUSION OF BLOOD. 



the cephalic extremity of the leech hardened in alcohol, dried and pulverized, a 

 decoction can be prepared by admixture with 0.9 per cent, saline solution (one 

 head is boiled for ten minutes with 6 cu. cm. of a saline solution, and then filtration 

 is practised). This decoction, when mixed in the proportion of 6 cu. cm. to 15 

 cu. cm. of blood obtained by venesection, suffices to maintain the latter in a fluid 

 state. The mixture will not coagulate for some time and can be used without fear 

 of injury. By this means the dreaded effect of the fibrin-ferment may be avoided. 



In Man the Infection of Animal Blood is Unjustifiable under Any Circumstances. 

 Direct transfusion of blood from the carotid of a lamb into the brachial vein 

 of a man was formerly employed not infrequently for therapeutic purposes. It 

 is to be remembered, however, that the erythrocytes of the sheep are rapidly 

 dissolved in human blood, and in consequence the most efficient constituents of 

 the transfused blood are destroyed. In a general way, it is found that the blood- 

 serum of many mammals has a rapid hemolytic effect upon the blood-cells of 

 other species of mammals. Thus, the serum of dog's blood has a rapid and intense 

 hemolytic action, while that of the horse and of the rabbit is relatively slow in 

 action. The erythrocytes of mammals possess a variable power of resistance to 

 the sera of other species of mammals. Thus, the erythrocytes of the rabbit, when 

 mixed with the blood of another species, are readily dissolved; while the cells of 

 the cat and the dog exhibit much greater resistance. The rapidity with which 

 erythrocytes are destroyed in the blood of another species is proportional to the 

 rapidity with which the blood-cells of the blood of the other species are dissolved 

 in the blood-serum of the recipient. Thus, for instance, rabbit's blood and lamb's 

 blood disintegrate within a few minutes in the circulation of a dog. When there 

 is a difference in the size of the blood-corpuscles of the two species, the hemolysis 

 can readily be observed in small specimens of blood obtained by puncture. As 

 the erythrocytes dissolve, the blood-plasma is stained red by the liberated hemo- 

 globin. A portion of this liberated material may supply the demands of metabo- 

 lism in the body of the recipient and be utilized for katabolism and anabolism, 

 while part of it is used up in the formation of bile. When, however, the quantity 

 of hemoglobin liberated by the erythrocytes is considerable, hemoglobin is excreted 

 in the urine, and to a less extent in the intestine, in the ramifications of the bron- 

 chial tree and into the serous cavities. In the last the hemoglobin may subse- 

 quently undergo absorption. Thus, in man hemoglobinuria has been observed 

 after the injection of more than 100 grams of lamb's blood. 



When blood from another species is transfused into an animal, the blood-cor- 

 puscles of the latter may undergo partial disintegration. This is the case when 

 the erythrocytes of the recipient are readily soluble in the serum of the trans- 

 fused blood. Upon this fact depends the great danger of transfusing a consider- 

 able quantity of heterogeneous blood into the rabbit, whose erythrocytes so 

 readily undergo solution. The same thing would happen if a dog's blood were 

 transfused into the veins of a man. In animals whose erythrocytes readily un- 

 dergo solution, as, for example, the rabbit, the injection of many kinds of sera, 

 as, for example, that of the dog, of man, of the pig, of sheep, and of the cat, is 

 followed by alarming symptoms, in accordance with the quantity of blood in- 

 troduced, namely: acceleration of respiratory frequency to the point of dyspnea, 

 convulsions, and even death from asphyxia. Under such circumstances all the 

 stages of hemolysis can be seen in a specimen of blood obtained by puncture. 

 Animals possessing more resistent erythrocytes, such as dogs, tolerate the injec- 

 tion of heterogeneous sera, as, for example, from sheep, neat cattle, horses and 

 pigs, without exhibiting such marked symptoms. The injected foreign serum, 

 being of feeble potency, is disposed of in the circulation of the recipient, before 

 it has time to attack, not to say dissolve, the blood-cells to any great extent. 



The process of hemolysis is accompanied by two other phenomena, which 

 render the transfusion of heterogeneous blood especially dangerous: i. Before the 

 erythrocytes are dissolved, they usually adhere together tenaciously and form 

 small masses, consisting of from 10 to 20 or more blood-cells, which are obviously 

 capable of obstructing large capillary areas. When these masses have been present 

 in the blood for some time they yield up their hemoglobin, leaving only the fused 

 remains of stroma. This forms a viscid, tenacious, stringy mass (stroma-fibrin) , 

 which likewise may occlude the smaller vessels. 2. The sudden appearance of 

 large quantities of dissolved hemoglobin in the blood of an animal may cause 

 extensive coagulation, principally in the venous system, but also in the larger 

 vessels throughout a considerable extent. The processes described may produce 

 death either suddenly or after a protracted course. Dissolved hemoglobin causes 



