142 EXUDATIONS. 



infiltrated, cretified, &c.). On microscopic investigation, most of 

 them are found to consist of fat-globules and molecular granules. 



Notwithstanding the rapidity with which the tuberculous exu- 

 dations are separated, and the circumstance that they are fre- 

 quently secreted to the last moment of life in tuberculous patients, 

 no attempts have as yet succeeded in obtaining for examination 

 a perfectly fresh, still fluid exudation, of which one might presume 

 with tolerable certainty that it would have been "tuberculised" had 

 the life of the sufferer been prolonged. Even should these attempts 

 succeed, it would still remain questionable whether the chemical in- 

 vestigation of these exudations would afford any further information 

 regarding the so-called tuberculous process than has already been 

 obtained from the analyses of the blood of tuberculous patients. 



There is no exudation which, when once formed, admits more 

 readily than the tuberculous of being studied with reference to 

 the length of time which it has existed, and the various metamor- 

 phoses which it has undergone ; thus we find on examining the 

 lungs of persons who have died from chronic tuberculosis, that the 

 most recent deposites are in the lower lobe, and the older forma- 

 tions in the upper one ; but still the most careful and numerous 

 micro-chemical and even microscopical investigations scarcely 

 yield any reliable results, and the various micro-chemical analyses 

 which I have made, in part conjointly with my friend Hasse, of 

 the most varied pulmonary tubercles, have not yielded the slightest 

 amount of scientific information. It would, therefore, be absurd 

 to enter circumstantially into the details of these series of experi- 

 ments, which are so frequently at variance with one another, 

 although at the period when these analyses were made, many 

 slight differences may have been passed over, which, in the present 

 advanced state of animal chemistry, might perhaps have thrown 

 some light on the subject ; but still the results are so different, 

 and even frequently so contradictory for entirely analogous objects, 

 that no support can be obtained for even the most general mode 

 of classification. We therefore withhold these details, trusting to 

 future investigations for more satisfactory results. 



The scattered facts yielded by works devoted to the subject 

 may be limited to the following points. The tuberculous mass, 

 when of recent date, contains, in addition to one of the protein- 

 bodies, which is soluble with more or less facility in acetic acid 

 and alkalies, a large quantity of fat, partly in very fine granules 

 and partly in vesicles. In tubercles of longer existence the fat 

 appears in much diminished quantities. The obsolete or cretified 



