///A BACILLUS AND THE BACTERIOLOGY OF TETANUS 225 



bodies have been introduced along with the spores deprived of their 

 toxins, and tetanus did not develop; but if the wounds containing the 

 foreign bodies became infected with other bacteria, tetanus developed 

 and the animal died. From such experiments it seems that a mixed 

 infection aids greatly in the development of tetanus when the infection 

 is produced by spores. 



Natural Infection. Here the infection may be considered as probably 

 produced by the bacilli in their spore state, and the conditions favoring 

 infection are almost always present. A wound of some kind has 

 occurred, penetrating at least through the skin, though perhaps of a 

 most trivial character, such as might be caused by a dirty splinter of 

 wood, and the bacilli or their spores are thus introduced from the soil 

 in which they are so widely distributed. If in any given case, the tissues 

 being healthy, the ordinary saprophytic germs are killed by proper dis- 

 infection at once, a mixed infection does not take place, and tetanus will 

 not develop. If, however, the tissues infected be badly bruised or 

 lacerated, the spores may develop and produce the disease. Gelatin is 

 found to contain occasionally tetanus spores. 



Occurrence and Duration of Life of Tetanus Bacilli. With regard to the 

 persistence of tetanus spores upon objects where they have found a 

 resting place, Henrijean reports that by means of a splinter of wood 

 which had once caused tetanus he was able after eleven years to again 

 cause the disease by inoculating an animal with the infective material. 

 The bacilli of tetanus are apparently more numerous in certain localities 

 than in others for example, some parts of Long Island and New Jersey, 

 have become notorious for the number of cases of tetanus caused by 

 small wounds but they are very generally distributed, as the experi- 

 ments on animals inoculated with garden earth have shown, and are 

 fairly common in New York City. In some islands and countries in 

 the tropics puerperal tetanus and tetanus in the newborn is very fre- 

 quent. Tetanus bacilli are found in intestines of about 10 per cent, of 

 horses and calves living in the vicinity of New York City. 



Tetanus in Man. Man and almost all domestic animals are subject to 

 tetanus. On examination of an infected individual very little local evi- 

 dence of the disease can be discovered. Generally at the point of 

 infection, if there is an external wound, some pus is to be seen, in 

 which, along with numerous other bacteria, tetanus bacilli or their spores 

 may be found. Although rather deep wounds are usually the seat of 

 infection, at times such superficial wounds, as an acne pustule or a 

 vaccination, may give the occasion for infection. Not only undoubted 

 traumatic tetanus, but also all the other forms of tetanus, are now 

 conceded to be produced by the tetanus bacillus puerperal tetanus, 

 tetanus neonatorum, and idiopathic tetanus. In tetanus neonatonun 

 infection is introduced through the navel, in puerperal tetanus through 

 the inner surface of the uterus. It should be borne in mind that when 

 there is no external and visible wound there may be an internal one. 



Toxins of the Tetanus Bacillus. It is evident from the localization 

 of the tetanus bacilli at the point of inoculation and their slight mul- 



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