METHODS OF EXAMINATION. 317 



a small degree of curative action. When it was injected im- 

 mediately after inoculation with the bacilli a certain number of 

 the animals survived, but in proportion as the symptoms, of the 

 disease (oedema, fever, etc.) were established, so was the curative 

 effect diminished, even though large doses of the serum were 

 employed. These results have been in the main confirmed by 

 other observers. The difficulties in the way of the therapeutic 

 use of such sera, which aim at the killing of infecting bacteria, 

 will be discussed in connection with Immunity : here it need 

 only be said that different bodies must be present in a serum in 

 order that it may be efficacious, and if all the factors are not 

 present, then a serum may have little or no action. In this con- 

 nection it may be mentioned that, according to de Nittis, the 

 serum of a pigeon immunised against anthrax will protect a 

 guinea-pig against a fatal infection. The serum of an immune 

 guinea-pig, on the other hand, will not protect a fresh guinea- 

 pig or a mouse against such an infection. 



Methods of Examination. These include (a) microscopic 

 examination; (^)the making of cultures ; and (c) test inoculations. 



(a) Microscopic Examination. In a case of suspected malig- 

 nant pustule, film preparations should be made from the fluid 

 in the vesicles or from a scraping of the incised or excised 

 pustule, and stained with a watery solution of methylene-blue 

 and also by Gram's method. By this method practically con- 

 clusive evidence may be obtained ; but sometimes the result 

 is doubtful, as the bacilli may be very few in number. In all 

 cases confirmatory evidence should be obtained by culture. 

 Occasionally they are so scanty that both film preparations made 

 from different parts and even cultures may give negative results, 

 and yet a few bacilli may be found when a section of the pustule 

 is examined. It should be noted that the greatest care ought to 

 be taken in manipulating a pustule before excision, as the diffu- 

 sion of the bacilli, into the surrounding tissues may be aided and 

 the condition greatly aggravated. The examination of the blood 

 in cases of anthrax in man usually gives negative results, with 

 the exception of very severe cases, when a few bacilli may be 

 found in the blood shortly before death, though even then they 

 may be absent. 



(b) Cultivation. A small quantity of the material used for 

 microscopic examination should be taken on a platinum needle, 



