SEROUS EXUDATIONS. 145 



because I found in two cases (in puerperal fever with pyaemia) 

 considerably more phosphates than one usually meets with in the 

 salts of the exudations. The occurrence of large quantities of 

 bile-pigment and biliary acids, urea, sugar, &c., in certain albu- 

 minous exudations must be regarded as purely accidental, and as 

 admitting of an easy explanation in individual cases. 



Rokitansky's serous dropsical exudations coincide perfectly with 

 the transudations which we treated of in vol. ii, pp. 308-331, but 

 we think we have sufficiently explained, both there and in the 

 introduction to the present section, the reasons which compel us 

 to separate the transudations from the exudations. No one can 

 deny that in some cases an exudation may become associated with 

 a transudation, or, conversely, a transudation may associate itself 

 with an exudation, but the two processes must in principle be 

 widely distinguished, as, in fact, they do occur distinct from each 

 other in most cases, leaving no grounds for confounding one with 

 the other. The erroneous idea that the plasticity of an exudation 

 depends only upon the quantity of fibrin which it contains, has led 

 many persons to doubt the propriety of separating exudations from 

 transudations, as we meet with plastic exudations without fibrin, 

 and non-plastic ones which contain fibrin ; but we think we have 

 satisfactorily shown from our own direct investigations, that the 

 plasticity of the exudations is constantly associated with the 

 presence of a certain amount of soluble phosphates, which occur 

 either in very small quantities or are even wholly wanting in the 

 transudations. As the phosphates and potash-salts can originate 

 only in the blood-cells, they cannot occur in large quantities in 

 the exudations, or render the transuded liquor sanguinis plastic, 

 unless there is true stasis and destruction of the blood-corpuscles, 

 when the contents of the latter transude through the lacerated or 

 uninjured walls of the capillaries. The formation of transudations 

 poor in phosphates and potash-salts, is solely dependent on a 

 retarding of the blood-current in the capillaries and on other 

 mechanical relations, and in no case depends upon a complete 

 stasis or destruction of the blood-corpuscles, in other words, it 

 never depends upon true inflammation. 



We do not, however, by any means incline to the view, that 

 the plasticity of an exudation is solely owing to the presence of 

 phosphates (although their influence on the formation of the 

 tissues in the case of animals, has been almost demonstrated by 

 direct observation) ; it is, on the other hand, very probable that 

 other substances may constitute essential requirements for pro- 



VOL. III. L 



