182 On tlie Microscopical Characters 



Schroeder Van der Kolk, who in 1846 first published his obser- 

 vations on the subject, and gave a fresh impetus to the labours of 

 Dr. Andrew Clarke and others in this country. How soon after 

 the accession of the malady, portions of lung tissue may be detected 

 in the sputa, is yet a question to which no definite answer can be 

 given, but at an advanced stage there is often very little difiiculty 

 in finding them. Thus Fig. 3 represents some fragments of fibrous 

 tissue taken from a small quantity of greenish purulent mucus 

 brought away with a single effort, but supposed by the patient, who 

 had himself been a nurse, to be of some import, judging from his own 

 sensations when it was expectorated. Patients frequently direct atten- 

 tion to particular portions of their sputa under a similar impression. 



As to the various modes of discovering the presence of lung tissue 

 in large or small masses of sj)utum, some remarks may be made here. 



First of all, some difiiculty may be experienced in removing 

 suggestive fiaorsels from the mass, on account of the viscid and ropy 

 nature of the surrounding mucus, more or less imbued with pus. 

 For this purpose Mr. Sansom has invented sharp spoon-blade 

 forceps, which will be found most effective and useful ; with this 

 instrument small portions may be easily taken from different parts 

 of the sputum, and separately examined. By careful compression 

 the mucus and pus corpuscles, young and old epithelial cells, may 

 be reduced to a thin film having a homogeneously granular appear- 

 ance, in the midst of which any lung tissue present may be distin- 

 guished by its continuity and high refractive power as compared 

 with that of the ground. The addition of a little acetic acid, how- 

 ever, will, on the principle previously explained, bring it out still 

 more clearly. 



When the quantity of expectoration is large it may not be easy 

 to make a selection of suitable portions for examination, but by 

 boiling the whole mass in caustic alkali the ropy plasticity of the 

 mucus is reduced to a limpid fluidity, with the total destruction of 

 the mucus and pus corpuscles. Any indestructible tissue present, 

 such as cotton and linen fibre, the elastic tissue of beef or mutton 

 used as food, or, what concerns us most, the fibrous tissue, &c., of 

 the patient's lungs, will be deposited at the bottom of the vessel, 

 from whence they may be readily removed with a pipette, and placed 

 under the microscope. Besides the elastic tissue, which exhibits 

 some slight change in its appearance by this treatment, we often 

 find portions of the basement membrane of the air-cells and smaller 

 bronchi, and even fragments of the bronchial radicles themselves, 

 with unequivocal though faintly marked rings. (Fig. 3 a.) By 

 pouring the sputum thus reduced into tall conical glasses such as 

 are used for urinary deposits, all the solid matters will quickly settle 

 at the bottom, so that some little discrimination may be required 

 to distinguish true lung tissue from other substances with which it 



