MICROSCOPICAL DIAGNOSIS. 



and the various colors seem to be due, in some cases at least, to the 

 presence of the coloring matter of the blood. The microscope will 

 be of great value in diagnosing the peculiar disease of the mouth, 

 known as aphtha. This chiefly occurs in infants but may extend 

 to adults who have suffered from long-exhausting disease. 

 Aphthae was first correctly described by Gruby, of Vienna, in 1842, 



J?ig. 9. Salirct. a, epithelial cells. />, salti'arv corpuscles. 



and was shown by him to be due to a vegetable parasite which is 

 distributed between the epithelial cells covering the lips, cheeks, 

 gums, tongue, pharynx and oesophagus, and according to Robin 

 sometimes the stomach, small intestines and rectum. The fungus 

 is classed by Robin under the genus oiiUum and called by him 

 oidium albicans. 



The spores of this fungus are round, oval, and irregular in 

 shape, sometimes nucleated, and varying from the 1-1500 to the 

 i-i2ooopf an inch in diameter. They are seen either floating free or 

 grouped together closely connected with the epithelium. Besides 

 the spores there are tubular, articulated filaments in which are ex- 

 ceedingly fine granules, which are sometimes seen in motion. To 

 examine for these spores some of the whitish matter is placed upon 

 a slide and a drop of potash solution added to make the cells and 

 mucus transparent; the whole is now covered with the thin glass arfd 

 examined under a power of from 400 to 750 diameters. 



SPUTA. 



All the normal and pathological ingredients of the oral 

 cavity may be found when examining the sputa for the purpose of 



