16 On Expec I orated Matter, 



liquor turbid ; nor for some time after the putrefactive pro- 

 cess had appeared. But these globules disappear with such a 

 proportion of sulphuric acid as detaches charcoal ; or of ni- 

 tric acid, and of liquid potash, as produce a clear solution r 

 altio by charring by fire. It is perhaps superfluous to re- 

 mark, that these atomic globules are quite different from 

 the air bubbles usually entangled in this kind of matter, as 

 perceived by the microscope ; the latter differ much from 

 the former, in being of far greater magnitude — in being less 

 numerous — in being transparent, and disappearing on agi- 

 tation, or heating the matter, or even by mere standing. 



'' For the most part this expectorated substance swims 

 on water; but by agitation or stirring to disengao;e air 

 bubbles, or by merely standing, it sinks. Some of the 

 lumps suddenly hawked up, immediately fall to the bottom 

 of a vessel of water. No signs of either acid, or alkali, 

 appeared on the trials of this matter with well known re- 

 agents, provided it was free from extraneous matter; but 

 it was apt to betray acidity from things taken with the food 

 or drink. 



" 4. Puriform matter, 1 have seen this matter expec-. 

 torated in several diseases in the quantity of two or three 

 ounces to half a pint in twenty-four hours, on some rare 

 occasions, vvithout any breach of surface. I believe it 

 would be considered by every one to be pus^ having the 

 properties commonly admitted to be those of this sub- 

 stance. It will, however, perhaps, only be just to call it 

 pur'ijhrm, for the present, as it appears to me probable, 

 that I shall hereafter be able to show that it possesses pro- 

 perties not belonging to pus of abscesses, although in the 

 obvious, or sensible properties, it is similar to such pus. 

 Accordingly this expectorated matter is not only opaque, 

 white, or yellowish, and thick as the richest cream, but 

 it also has not more tenacity than cream. It is not apt to 

 entangle air, and therefore it immediately mingles with 

 water, rendering it milkv ; and presently subsides to the 

 bottom, leaving the water clear, or at least whey-coloured. 

 It appears to the naked eye uniform in its texture ; and nearly 

 so under the simple lens : but under the microscope thou- 

 sands of globules similar to those of the blood are seen, 

 which are indestructible as those above related belonging 

 to another kind of expectorated matter. 



*< The substance, of which I am now speaking, is most 

 frequently excreted in the latter stages of pulmonary phthi- 

 sis, for many weeks successively. It is taken for granted 

 that this matter is from a breach of surface or ulceration > 



but 



