AND ITS RELATIONS TO THE LIVING ORGANISM. 287 



nidus, and will yet exhibit its full potency on the very first case in which 

 opportunity maybe given for its introduction into the system of u puerperal 

 patient. 1 The -same kind of liability is displayed in the subjects of severe 

 injuries, and in those exhausted by long-continued muscular exertion, among 

 whom, also, there is not only a state of general depression of the vital powers, 

 but also a special source of decomposing matter in the svstem ; for there is 

 evidence that "surgical fever" may be induced in them, by the introduction 

 of a zymotic poison derived from a variety of external sources (amongst 

 others, from patients affected with puerperal fever), such as would have no 

 erlec't upon a healthy subject ; and, moreover, that overcrowding in hospitals 

 has a special tendency to increase this liability. 2 Thus, then, we may affirm 

 with strong confidence that the special liability to Zymotic diseases, which 

 determines their selection of individuals when epidemically prevalent, de- 

 pends upon the previous condition of the blood of the subjects who are thus 

 " predisposed" to their invasion; and more especially on the presence of 

 fermentable matters, resulting from the ordinary processes of disintegration, 

 which, in the state of perfect health, are eliminated as fast as they are formed, 

 but of which an accumulation is prone to take place, either when there are 

 special sources of an augmented production, or when the excretory opera- 

 tions are imperfectly performed. 3 And it would further appear that the 

 continued accumulation of such matters may itself become a source of cer- 

 tain forms of Zymotic disease, which may thus originate de novo in the 

 system, and which may thence be propagated to other individuals in some 

 of the modes already specified ; of this we have notable examples in ery- 

 sipelas and the "pustule maligne." 



224. It is not only, however, in the class of Zymotic diseases that we 

 seem distinctly able to trace the operation of morbid poisons circulating in 

 the blood ; for there are numerous other maladies, of whose origin in a like 

 condition there can be no reasonable doubt; and these are in some respects 

 more closely analogous than the preceding to the disordered states induced 

 by the introduction of toxic agents. For in those of which we have now to 

 speak, the action is destitute of any analogy to fermentation, and its po- 

 tency is strictly proportionate, in each case, to the amount of the dose that 

 is in operation. Here, too, we have a connecting link afforded by those 

 disordered states of the system, which depend upon an undue accumulation 

 of poisons normally generated within it, in consequence of some obstacle to 

 their elimination." Thus, the retention of urea or of uric acid, of carbonic 

 acid, biliary matter, lactic acid, or of other substances which are normal 

 products of the waste or disintegration of the body, in the blood, are as true 

 instances of poisoning as if these substances had been directly injected into 

 the bloodvessels ; and the evil is of course increased, when (as frequently 

 happens) augmented production is concurrent with imperfect elimination. 



225. In all cases, therefore, one of the first questions which the intelligent 

 Practitioner will feel called upon to decide, is, whether the malady he has 

 to treat originates in the state of the Blood, or in a disorder purely local ; 

 and if he feel justified in referring it to the blood, whether it merely depends 



1 This is shown by the instances, unhappily of no unfrequent occurrence, in which 

 practitioners who have unfortunately become the vehicles of the puerperal poison, 

 and have conveyed it to several patients in succession, have experienced the same 

 direful results immediately on resuming obstetric attendance, after a lengthened in- 

 terval of suspension from it, and even from professional employment of every kind. 



2 See Prof. Simpson, On the Analogy between Puerperal and Surgical Fever, in the 

 Edin. Monthly Journ., vol. xi, p. 414; and vol. xiii, p. T2. See also Bryden, .Report 

 on Cholera, 1869. 



3 For a fuller exposition of this doctrine, see the Brit, and For. Med.-Chir. Rev., 

 vol. xii, p. 159 et seq. 



