ORIGIN OF THE SOLID TISSUES. 451 



the similarity of result) that it has been introduced through some obscure 

 channel, probably. the lungs. The final symptoms which are common to all 

 these diseases have been well described by Dr. Williams,* under the title of 

 Necrsemia, or death by 'depravation of the blood. " Almost simultaneously, 

 the heart loses its power, the pulse becomes very weak, frequent, and un- 

 steady : the vessels lose their tone, especially the capillaries of the most vas- 

 cular organs, and congestions occur to a great amount; the brain becoming 

 inactive, and stupor ensues ; the medulla is torpid, and the powers of respira- 

 tion and excretion are imperfect : voluntary motion is almost suspended ; se- 

 cretions fail; molecular nutrition ceases; and at a rate much more early than 

 in other modes of death, molecular death follows close on somatic death, that 

 is, structures die and begin to run into decomposition as soon as the pulse and 

 breath have ceased ; nay, a partial change of this kind may even precede the 

 death of the whole body ; and parts running into gangrene, as in the carbuncle 

 of plague, the sphacelous throat of malignant scarlatina, and the sloughy sores 

 of the worst forms of typhus, or the putrid odour exhaled even before death 

 by the bodies of those who are the victims of similar pestilential disease, are 

 so many proofs of the early triumph of dead over vital chemistry." " The 

 appearance of petechiae and vibices on the external surface, the occurrence of 

 more extensive hemorrhage in internal parts, the general fluidity of the blood, 

 and frequently its unusually dark or otherwise altered aspect, its poisonous 

 properties as exhibited in its deleterious operation on other animals, and its 

 proneness to pass into decomposition, point out the Blood as the first seat of 

 disorder ; and by the failure of its natural properties and offices as the vivifier 

 of all structure and function, it is plainly the medium by which death begins 

 in the body." 



VI. Origin of the Solid Tissues Separative Processes. 



593. It has been shown that the Blood contains a substance (Fibrin), which 

 is prepared to become organized, or to take upon itself that peculiar kind of 

 molecular arrangement, anatomically characterized as structure ; and which 

 possesses what the physiologist terms vital properties ; but it has also been 

 shown, that the conversion of this Fibrin into any higher form of organized 

 structure than simple fibrous tissue, requires the influence of a previously-ex- 

 isting organism. In the development of the Embryo, the germ of the first 

 cell appears to be supplied by the male parent ; whilst the nutriment at the 

 expense of which it is evolved is supplied by the female. In the subsequent 

 growth of the organism, the materials are derived from the food ingested ; and 

 the conversion of these into organized tissue depends upon the properties of 

 the structure already formed, which, whilst itself decaying, liberates the 

 germs of new cells, and thus makes preparation for its renewal. The pro- 

 cesses by which these cells are converted into the several kinds' of organic 

 structure, that compose the fabric of the higher animals, are in many instances 

 very complex ; and can only be traced by an attentive examination of their 

 several stages. Whether they are observed, however, in the first Develop- 

 ment of the Embryo, or in the Reproduction of lost parts, they seem to be 

 essentially the same. In fact, among the lowest tribes of Animals, we find 

 these two conditions blended, as it were, together ; for the process of repara- 

 tion may be carried in them to such an extent as to regenerate the whole 

 organism from a very small portion of it. In the Hydra, or Fresh-water 

 Polype, there would seem to be scarcely any limit to this power ; for, if the 

 body of the animal be minced into the smallest possible fragments, every 



* Principles of Medicine, [Am. Ed. by Dr. Clymer, p. 373.] 



