58 Drv Beale, on the Germinal Matter of the Blood. 
occurred quite suddenly^ and as it were^ en 7nasse, the living 
matter would become resolved into soluble substances ■which 
possess neither the properties of the red colouring matter of 
the blood nor those of the fibrin. 
I think, then, that the production of the material we know 
as fibrin is due to that gradual death of minute particles of 
the living matter of the white, and small colourless, corpuscles 
which takes place under ordinary circumstances when blood 
escapes from the vessels of the living body. The blood does 
not die the very instant it leaves the vessels, and, as is well 
known, it may be caused to retain its vitality much longer 
under some conditions than others. It is even probable that 
these particles of living matter may absorb nutrient matter 
and increase for some time after the blood has left the vessel, 
so that it is possible not only that some of the fibrin, but that 
the living matter from which it resulted, may have been 
produced after the blood was removed from the organism. A 
white blood-corpuscle will live and move for hours after the 
blood has been drawn from the body. 
On the other hand, in certain cases in which it is said that 
the fibrin does ''not coagulate/^ it may be that all the parti- 
cles of living matter are instantly destroyed and soon after- 
wards break down into substances which do not possess the 
property of coagulation. 
Fibrin having been produced, may at once pass into the 
solid state, or it may be difi'used through the blood in a state 
of extreme tenuity. This state may be maintained for a 
considerable period of time by the chemical and physical 
action of certain substances present. The density of the 
fluid through which it is diffused, probably exerts a very 
powerful influence upon its further condensation. A slight 
alteration of circumstances may cause fibrin once formed to 
contract, and the diffused transparent material gradually to 
become coherent, so as to form threads or masses (fibrin) 
which refract the light more highly than serum or " liquor 
sanguinis or a web of fibres makes its appearance in the 
fluid, from which it seems to be precipitated. These fibres, 
so delicate at first as to be quite invisible, gradually become 
thicker as the process of contraction proceeds, until a firm 
clot results. For some time afterwards the contraction goes 
on, so that much fluid is expressed from the meshes of the 
clot, and the fibrin is found to be very elastic. 
It is as if the particles of matter of which the fibrin is com- 
posed had been prevented from exerting their ordinary 
attraction by the conditions which existed, but a slight 
change having allowed the ordinary attraction to come into 
