406 [Jan. 15, 



formed, from the fact that the analyses of albumen of egg, and the 

 casein which the milk contains, differ little from each other, and be- 

 cause the analysis of the milk of an animal, a few days before and 

 after parturition, shows that albumen is found in the place of casein. 

 On subjecting, however, milk to experiment, no fibrin was found 

 after the lapse of twenty-four hours. 



This may be due to either of two causes : first, the casein in the 

 milk may not be in a fit state for undergoing the change before it 

 has been acted on by the various digestive secretions, or, secondly, 

 because in the dilute and fluid state in which it occurs in milk it 

 does not offer sufficient resistance to the passage of the bubbles of 

 oxygen to retain the gas sufficiently long for each bubble to have 

 time to produce an effect. In all my experiments I have found (other 

 conditions being equal) the slower the bubbles passed through the 

 liquid material, and the more viscid the fluid was, the greater was 

 the amount of fibrin produced. This may possibly in some degree 

 account for the non-formation of fibrin when oxygen was passed 

 through milk. I tried the effect of oxygen upon fresh grape-juice, 

 but was unable to form any fibrin from it. Further experiments are 

 required upon various vegetable juices. 



I next experimented upon the oxidation of gluten, which was ob- 

 tained from wheat*flour by the ordinary method. This was digested 

 in gastric juice for twelve hours, and then filtered. After the clear 

 liquid had been subjected to oxidation for some hours, small threads 

 of a substance were formed. When a portion of this was placed 

 under the microscope, no difference could be detected between it and 

 ordinary fibrin, 



From these experiments, it seems to me that the following con- 

 clusions may be drawn : 



First, that fibrin is produced by the direct action of oxygen on 

 albumen. 



Secondly, that the alkalies and alkaline salts prevent the appear- 

 ance of fibrin when albumen is acted upon by oxygen. 



Thirdly, that the formation of fibrin from albumen is accom- 

 panied by the evolution of sulphur, phosphorus, and carbonic 

 acid. 



Fourthly, That a temperature ranging between 98 and 110 Fahr. 

 promotes the artificial formation of fibrin. 



