266 THE BLOOD. 



the blood with water, that the haemoglobin is separated from the stroma 

 and passes into the watery solution. This process is called haemolysis, 

 (see Chapter II). 



A haemolysis may also be brought about by alternately freezing and 

 thawing the blood, as well as by the action of various chemical substances, 

 which act as protoplasmic poisons. These bodies are ether, chloroform 

 alkalies, bile-acids, solanin, saponin, and also the saponin substances, 

 which have a very strong haemolytic action. Of special interest in this 

 regard are the haemolysines, which act like toxines. These haemolysines 

 may be metabolic products of bacteria and may be formed by higher 

 plants and by animals, such as snakes, toads, bees, spiders, and others. 

 Finally, the haemolysines or globulicidal bodies, occurring normally in 

 blood-sera or produced in the immunization of the blood, also belong here. 



It seems that haemolysis is brought about in various cases in different ways. 

 In the haemolysis by means of water we are probably dealing with a destruction 

 or rupture of the boundary-layer, while such bodies as ether, chloroform, alkalies, 

 bile-acids, and saponin substances, which dissolve lipoids or form combinations 

 therewith, in this way cause the passage of the haemoglobin to the outside 

 (ROPPE, RANSOM and ROBERT, PESKIND, PASCUCCI). The action of other 

 haemolysines, such as snake-venom and tetanotoxine, seems to be an action con- 

 nected with the lecithin (KEYES, PASCUCCI 1 ). 



When the haemoglobin is separated from the so-called stroma by a 

 sufficiently strong dilution with water the stroma is found in the solution 

 in a swollen condition. By the action of carbon dioxide, by the careful 

 addition of acids, acid salts, tincture of iodine, or certain other bodies, 

 this residue, rich in proteins, condenses, and in many cases the form of 

 the blood-corpuscles may be again obtained. This residue, the so-called 

 ghosts or stromata of the blood-corpuscles, can also be directly colored 

 in dilute blood by methyl violet and in this way detected (KOPPE), and 

 attempts have been made to isolate it for chemical investigation. In the 

 following pages we mean by the name stroma only that residue that 

 remains after the removal of haemoglobin and other bodies soluble in 

 water. 



To isolate the stromata from the blood-corpuscles, they are washed first 

 by diluting the blood with 10-20 vols. of a 1-2 per cent common salt 

 solution and then separating the mixture by centrifugal force or by 

 allowing it to stand at a low temperature. This is repeated a few times 

 until the blood-corpuscles are freed from serum. These purified blood- 

 corpuscles are, according to WOOLDRIDGE, mixed with 5-6 vols. of water 

 and then a little ether is added until complete solution is obtained. The 

 leucocytes gradually settle to the bottom, a movement which may be 



1 Koppe, 1. c.; Peskind, Amer. Journ. of Physiol., 12; Ransom and Robert, cited 

 by Pascucci, Hofmeister's Beitrage, 6; Ryes, Zeitschr. f. physiol. Chem., 41, and Berl. 

 klin. Wochenschr., 1904. 



