TETANUS 53 



This method is not likely to succeed where, as is frequently 

 the case, the bacilli are present in a mixture containing 

 numerous other sporulating anaerobes. In this case the 

 simplest method is to make surface cultures on agar slope 

 from the pus after heating (using the method described on 

 p. 17) and incubating them in Buchner's tubes. These are 

 simply large, wide test-tubes, closed by well-fitting india- 

 rubber bungs. Some contrivance (indentations or a con- 

 striction in the tube or a piece of metal bent into a suitable 

 shape) is used to keep a culture-tube an inch or so off the 

 bottom when placed inside. To use it, place i gramme (or 

 thereabouts, the exact amount does not matter) of dry pyro- 

 gallic acid at the bottom of the tube. Then add 10 c.c. of a 

 10 per cent, watery solution of caustic soda, insert the culture- 

 tube, and apply the bung, which should be greased with vase- 

 line or ung. resinae. Incubate. Tetanus colonies are greyish 

 and have a peculiar granular appearance which is fairly char- 

 acteristic. 



The tetanus bacillus forms gas in deep culture in glucose 

 agar, but less abundantly and more slowly than do the 

 organisms with which it is frequently associated. Choose, 

 therefore, a region of the growth free from gas if possible for 

 microscopic examination, if this is to be made within the first 

 day or two. 



INTERPRETATION OF RESULTS. 



If bacilli having the above characters are found in films, the 

 diagnosis of tetanus must not be considered as being abso- 

 lutely proven, for there are other bacilli which might be mis- 

 taken for those under discussion; but the probability that the 

 patient will develop the disease is so strong that steps should 

 be taken accordingly. The wound should be scraped and 

 thoroughly treated surgically, and antitoxin should be given. 

 If the deeper portion of the glucose-agar stab shows 

 the tree-like growth which has been described and contains 

 slender drumstick bacilli, the case is strengthened, even 

 although the upper part of the medium is contaminated with 

 other organisms. 



The only way in which the bacilli can be recognized with 



absolute certainty is by means of animal experiments; this is 



" a very certain method, and one that can be carried out in the 



absence of pure cultures. The material is diluted with some 



