HJEMORRIIAGIES. 2U 



great deal of air may swim, and mucus that is free from air 

 may sink. 



5. From the mixture which is discernible in ,the matter 

 brought up ; for if a yellow or greenish matter appears sur- 

 rounded with a quantity of transparent or less opaque and less 

 coloured matter, the more strongly coloured matter may be gen- 

 erally considered as pus ; as it is not easy to understand how 

 one portion of the mucus of the lungs can be very considerably 

 changed, while the rest of it is very little so, or remains in its 

 ordinary state. 



" There is no certainty in this mark ; it might have been 

 left out ; and if other circumstances do not concur, no conclu- 

 sions can be drawn from it." 



6. From the admixture of certain substances with the matter 

 thrown out from the lungs. To this purpose we are informed 

 by the experiments of the late Mr. Charles Darwin : (a.) That 

 the vitriolic acid dissolves both mucus and pus, but most readi- 

 ly the former. That if water be added to such a solution of 

 mucus, this is separated, and either swims on the surface, or, 

 divided into flocculi, is suspended in the liquor; whereas, when 

 water is added to a like solution of pus, this falls to the bottom, 

 or by agitation is diffused so as to exhibit an uniformly turbid 

 liquor. (b.) That a solution of the caustic fixed alkali, after 

 some time, dissolves mucus, and generally pus ; and, if water 

 be added to such solutions, the pus is precipitated, but the 

 mucus is not. From such experiments it is supposed, that pus 

 and mucus may be certainly distinguished from each other. 



7- From the expectoration's being attended with a hectic 

 fever. A catarrh, or expectoration of mucus, is often attended 

 with fever ; but never, so far as I have observed, with such a 

 fever as I am presently to describe as a hectic. This, in my 

 opinion, is the most certain mark of a purulent state in some 

 part of the body ; and if others have thought differently, I am 

 persuaded that it has been owing to this, that, presuming upon 

 the mortal nature of a confirmed or purulent phthisis, they have 

 considered every case in which a recovery happened, as a catarrh 

 only ; but, that they may have been mistaken in this, shall be 

 shown hereafter. 



DCCCLVII. Having thus considered the first part of the 



VOL. II. Q 



