204 MEDICAL BACTERIOLOGY 



avoiding the production of hemorrhage, serum or serum and scrapings is ob- 

 tained from the floor of the ulcer with a capillary tube. If adjacent glands 

 are enlarged, some of the contents of these is removed with a syringe. This 

 material is examined unstained with the dark-field microscope, or stained, as 

 described in the chapter on treponema pallidum. 



MADURA FOOT AND ACTINOMYCES 



In these infections the pus is searched for granules and these are crushed 

 between a slide and a cover glass and examined microscopically, unstained and 

 after staining. When granules are not found, the pus is spread on slides and 

 examined microscopically before and after staining. 



FAVUS, RING WORM, PITYRIASIS VERSICOLOR, ERYTHRASMA AND BLASTOMY- 



CETIC DERMATITIS 



Bacteriological diagnosis in the diseases caused by the higher forms of bac- 

 teria is usually based upon microscopic examination alone, cultures may be 

 made for more accurate classification. In the above-named diseases, the 

 method of procedure is the same, some hairs, portions of the crust or scab and 

 scrapings from the border line between the diseased and healthy skin should be 

 obtained and examined separately. A number of slides should be prepared 

 and examined in every case. The material to be examined, whether hair, crust 

 or scrapings, should be placed in a drop of 20 to 40 per cent, potassium hydrate 

 solution and a cover glass dropped upon it. The slides are then allowed to 

 stand at room temperature for several minutes. Then some 'are examined 

 without heating, others after gently warming for several minutes and others 

 after heating until steam arises. 



In every case where the microscopical examination and other findings do 

 not disclose the exact nature of the offending organisms, cultures should be 

 made. 



LEPROSY 



In every suspected case of leprosy the anterior nares should be examined 

 whether lesions appear there or not; a sterile cotton swab is passed over the 

 mucous membrane and then rubbed on a slide. Skin ulcers should be cleansed 

 to free them of contamination and slides made from scrapings removed from 

 the floor of the ulcer. 



These slides should be stained as when examining for tubercle bacilli. 



DISEASES OF THE EYE 



The lids are subject to all of the infectious diseases that affect the skin and 

 the technique of bacteriological diagnosis is the same as in similar diseases of 

 the skin of other parts of the body. 



The lachrymal apparatus is more frequently attacked by the pyogenic or- 

 ganisms than by other bacteria. When a bacteriological diagnosis of an infec- 

 tion of any part of the lachrymal apparatus is desired, the affected and con- 



