172 



and without alcohol can hardly be compared the one with the other. 



To Atwater and Benedict's experiments it must be objected (as 

 DuRiG has also pointed out) that their determinations covered lengthy 

 periods at the close of which a favourable influence may have been 

 neutralized by a subsequent unfavourable action, so Ihat the totals 

 do not vary much and are not typical of the real process. 



Our conclusion is that directly or indirectly alcohol not only pro- 

 duces energy for muscular exercise, hut also that after the taking in 

 of alcohol the latter occurs more economically at the outset, even 

 under the unfavourable condition of a high temperature of the sur- 

 roundings. This favourable influence of the alcohol gradually decreases 

 and ultimately alters to the opposite in one of the subjects. 



Utrecht. Institute of Hygiene. 



Piiysiology. — "On fibrin in sol and gel state. Likewise a contri- 

 bution to our knowledge of the blood-coagulation problem." By 

 E. Hekma. (Communicated by Prof. Hamburger). 



(Gommunicated in the meeting of April 25, 1913). 



The coagulation of blood is based, as we know, upon the transition 

 of a coagulable albuminous substance, found in circulating blood 

 and called fibrinogen, into a solid substance, fibrin. 



Fibrin forms threads, fibrils; these fibrils may form a network 

 which can enclose the blood-corpuscles. Hence, when the blood 

 which flows from a wound coagulates, a plug is formed which 

 can close the wound, whilst if for instance the blood, spouting from 

 an opened blood-vessel, is left to itself in a glass, the fibrin-network 

 with the enclosed blood-corpuscles forms the so-called blood-clot. 

 If, however, the blood, flowing from a blood-vessel is not left to 

 itself, but beaten up, then the fibrinogen is turned into fibrin in the 

 form of a compact, white mass of fibrils. This fibrin, however, 

 should not be looked upon as pure fibrin, that is to say as the 

 coagulated substratum of fibrinogen. For besides the latter substance, 

 which forms its main component part, blood-platelets and likewise 

 red blood-corpuscles and leucocytes oi' rests of them, not to mention 

 other substances, pass into the fibrin. 



The study of the problem relating to the nature of blood-coagu- 

 lation, in other words the formation of fibrin is mainly occupied 

 with two questions. First with the question : what relation exists 

 between fibrinogen and fibrin, and secondly: what agents cause 

 fibrinogen to pass into fibrin. 



