158 EXUDATIONS. 



phorus may always be detected in the residue which is insoluble 

 in cold ether. 



Normal pus generally contains from 14 to 16^ of solid con- 

 stituents. The purulent exudations which occur in serous cavities 

 and bad ichorous pus, often contain a smaller amount of solid 

 consti tutents. These solid matters contain from 5 to 6 of mineral 

 or inorganic substances in the pus of healthy persons, whilst the 

 amount may rise to 10 or even ]4 in bad pus and in watery 

 transudations. The ratio of the insoluble to the soluble salts in 

 healthy pus varies from 1:7 to 1:9, whilst in bad pus it 

 often = 1 : 15 or even 23. It follows from these observations, 

 that in bad pus a greater or smaller quantity of simple transudation 

 must have become mixed with the true plasma of the pus. 



The insoluble salts of pus are those which usually accompany 

 the protein-bodies, namely, the phosphates of lime and magnesia, 

 in addition to which there is always a variable amount of car- 

 bonate and sulphate of lime generated by the process of incinera- 

 tion. There is, moreover, always some oxide of iron to be detected 

 in the ash of pus, even when no trace of blood-corpuscles is to be 

 discovered in the fresh fluid. 



Chloride of sodium constitutes the principal part of the soluble 

 salts of pus. H. Nasse long since drew attention to the fact that 

 the serum of the pus and its solid residue contained three times more 

 of this substance than the blood-serum and its solid residue ; and 

 even when the quantity of the chloride of sodium of the whole pus 

 is compared with that of the blood-serum, the former is always found 

 to be the larger. A comparison between the chloride of sodium in 

 the serum of the pus, and that which is present in pus rich in 

 corpucles, shows that here, as well as in the blood, the larger pro- 

 portion of this salt is dissolved in the intercellular fluid, and that 

 a very small quantity only is contained in the pus-corpuscles. 



The ash of the pus does not contain a very large amount of 

 soluble phosphates, but, as we have already stated, no approximate 

 estimate or definite relation can be established between these and 

 the other salts. The quantity of soluble phosphates in the ash of 

 different kinds of pus varied between 3 and 10. Moreover, the 

 quantity of potash in the different kinds of pus did riot admit of 

 being definitely determined ; this much only was constantly ob- 

 served, that there was always more potash present than in the 

 intercellular fluid of the blood. The experiments made on the pus 

 of rabbits did not lead to any more definite results. 



I succeeded by the same methods which I employed in the 



