80 BACTERIOLOGICAL DIAGNOSIS. 



not decolorised a fresh specimen should be prepared 

 and immersed in the acid for a longer period. 



ACTINOMYCOSIS. 



Actinomycosis is very closely allied to tuberculosis ; 

 the lesions appropriate to the two diseases are almost 

 identical in histological appearance, and the granuloma 

 which occurs in actinomycosis goes on to fibrosis or to 

 the formation of "cold abscesses " just as a tubercle 

 may do. The formation of fibrous tissue is most 

 marked in cattle, and in them the disease is more 

 chronic ; suppuration is more common in man, and the 

 disease runs a more rapid course. 



The pus from an actinomycotic abscess is often viscid 

 and contains a greater or smaller number of small 

 greenish, yellow, or brownish nodules. They are about 

 as large as the head of a very small pin, and are quite 

 opaque ; under the low power of the microscope such 

 a granule has a coarsely granular appearance, and looks 

 something like a raspberry. If nodules presenting these 

 appearances are found in any specimen of pus, whatever 

 be its origin, a careful microscopic examination should 

 be made to determine its nature. This is not difficult. 



Method. Place some of the pus which contains these 

 granules on a clean slide and press another slide upon 

 it so as to crush the granules, dry, fix, and stain by 

 Gram's method. 



Tumours removed or incised at an operation, or 

 organs removed at a post-mortem examination, should 

 have their cut surfaces rubbed upon the surface of a 

 slide and the film thus obtained treated in a similar 



