124 EXUDATIONS. 



logical products is, moreover, essentially obstructed by numerous 

 relations. Every pathologist knows how rare it is to meet with 

 very recent exudations in the dead body ; how difficult it generally 

 is to determine the age of an exudation, even with any degree of 

 accuracy ; how insufficient, even under the most favourable cir- 

 cumstances, is the quantity of the material in which we have to seek 

 for special constituents; and how rapidly decomposition sets in 

 after death, even while the body is yet warm. 



We would here touch upon only one of these impediments. 

 We have already often had occasion to notice in this work the 

 admirable contributions made by Liebig to our knowledge of the 

 metamorphosis of animal matter by his investigation of the mus- 

 cular fluid ; these experiments were, however, conducted under 

 very favourable circumstances ; for independently of his genius and 

 dexterity, we need only refer to the mass of the material which he 

 employed, and to the fact that perfectly fresh materials and 

 analogous objects could be easily procured for comparison. It was 

 reserved for Liebig and Schlossberger to re-discover creatine, to 

 which Chevreul had long before drawn attention, whilst to them 

 also belongs the merit of making us more intimately acquainted 

 with its nature. Notwithstanding the favourable circumstances 

 already indicated, Liebig himself was only able to indicate a few 

 substances, as inosic acid, &c. Moreover, Scherer's inosite can 

 only be exhibited when we have large quantities of material at 

 command ; and it seems, as it were, to evade the experimenter, by 

 becoming converted into butyric acid, if the fresh material and the 

 separate extracts are not carefully guarded from the risk of decom- 

 position. In a word, whilst even the qualitative investigation of 

 objects derived from healthy animals has to contend with such 

 difficulties that very few animal juices admit of being very accu- 

 rately examined, the qualitative analysis of pathological products 

 is opposed by insurmountable obstacles.^ We must, therefore, wait 

 till the physiological juices and their metamorphoses in the animal 

 body have been more attentively studied, before we venture to sub- 

 mit the solid or fluid pathological products, the more or less remote 

 allies of the blood and of its protein-bodies, to a truly scientific 

 qualitative investigation. 



If we have, therefore, very slight prospect of being able to 

 trace pathological processes by a qualitative examination of exuda- 

 tions, or of attaining any scientific aim by such a mode of procedure, 

 we are led to inquire, with some hesitation, whether the quanti- 

 tative analysis of these products would be attended by any better 



