Elements of human physiology / by L. Hermann ; translated from the sixth edition by Arthur Gamgee.

  • Gamgee Arthur, 1841-1909.
Date:
1878
Catalogue details

Licence: Public Domain Mark

Credit: Elements of human physiology / by L. Hermann ; translated from the sixth edition by Arthur Gamgee. Source: Wellcome Collection.

Provider: This material has been provided by the Royal College of Physicians of Edinburgh. The original may be consulted at the Royal College of Physicians of Edinburgh.

    98/620 (page 78)
    cally, the ferment. Both the fibrin generators are soluble in alkalies and acids and in solutions of common salt; they are soluble in water if a stream of oxygen be passed through it. The ferment is obtained by adding alcohol to blood, and exti-acting the tlioroughly dried and filtered residue with water. Blood allowed to flow directly from an artery into alcohol yields no ferment. On mixing solutions of fibrinogen and the fibrinoplastic substance in the presence of the ferment, fibrin separates first as a gelatinous substance, which afterwards contracts; the quantity of these two substances determines the amount of fibrin, to form which they appear to combine, although in proportions which are not constant. The amount of ferment present merely influences the rapidity of the separation of fibrin. Serum contains an excess of fibrinoplastic substance (that of ox's blood contains 0-7-0-8, of the horse 0-3-0'6 per cent). Presence of non-crystallizable haemoglobin, of carbon, platinum, &c. hastens the formation of fibrin, when all other conditions are present. If solutions of the fibrin generators and of the ferment are deprived of oxygen, by passing hydrogen through them, before they are mixed, no fibrin is formed (A.. Schmidt). The connection between the above and the other phenomena accompanying the death of the blood, particularly acidification, is unknown. Blood which has undergone these changes, if kept longer, particularly if defibrinated, gradually loses the whole of its oxygen, carbonic acid taking its place : at the same time putrefac- tion sets in. The phenomena accompanying its death are the result of the cessation of an influence exercised constantly upon the blood during life, by the living walls of the vessels (Briicke*). The blood does not coagulate as long as it circulates in the vessels, so that every portion of it constantly comes in contact with their living walls ; nor does it coagulate if, after being drawn, it is in contact with a living vessel (as, for instance, when frog's blood is placed, over mercury, in contact with a pulsating frog's heart, Briicke). On the other hand, it coagulates after it has been drawn from the vessels, or in the vessels, after their death, or even in living vessels, if at any point stagnation of the blood occurs, so that the central layers are removed from the influence of the walls. Many precise accounts concerning the causes of the process of coagulation are here passed over, because they have not been verified. According to our present views of fibrin formation, BrUcke's law would be expressed as follows: the influence of the living vascular wall is to hinder the formation of the fibrin ferment, or to destroy it continuously as soon as it is formed.* All the phenomena which characterize the death of the blood are hastened by high temperatures, and by the contact of the blood with foreign bodies (as by stirring\ also by air (blood coagulates more quickly in open vessels than over mer- cury). 1 Briicke, British and Foreign Med. Chir. Bevietv, 18o7. p. 183. rXhe reader who is intereked in tiiis subject is advised to study the most susgestive Croonian Lecture by Professor Lister (Proceedings of the Royal Society, 18Co), in which he will find many facts which are opposed to BrUcke's theory, and which it is di&cult to explain even with the light of Schmidt's most recent researches.]