292 BACTERIA. 



are consequently much less favourable for the continued 

 existence of the tetanus bacillus. 



The spores of the tetanus bacillus seem to have a remark- 

 ably wide distribution. Originally they were only cultivated 

 from garden soil, but successful inoculations have since been 

 made with such material as the sweepings of a hay-loft, and the 

 dust that had accumulated on the furniture of horses. The 

 specific bacillus has been found on the grime on a man's hand, 

 and on imperfectly cleansed surgical instruments. Tetanus 

 is said to be specially associated with the horse, but the more 

 recent observers insist that this is simply because the horse is 

 susceptible to the action of the bacillus and its poison, and 

 because the germs have such a widespread — ^in fact, an almost 

 universal — distribution. How universal this distribution is 

 may be gathered from the fact that M. Bossano, who was 

 able to obtain the soil from forty-three different regions in 

 various parts of the globe, got positive results with twenty- 

 seven of them. With the soil from these forty -three places 

 he inoculated a number of animals, introducing a small por- 

 tion, about the size of a pea, into a little subcutaneous pocket 

 of a white mouse or a guinea-pig, and with the soil obtained 

 from twenty-seven of these places tetanus was produced in 

 from two to four days. He says of the soil obtained from 

 England, that from Bath produced tetanus in two out of 

 three white, mice inoculated, both of them dying in about 

 two days. Soil from Portsmouth did not contain tetanus 

 bacilli, whilst that from Plymouth and from Manchester 

 caused the death of some of the animals that were inoculated 

 with it, all the characteristic symptoms of tetanus being 

 developed. Speaking colloquially, a worker at the Brown 

 Institute told a friend that they grew the tetanus bacillus in 

 the garden there. From his experiments Bossano concluded 

 that soils which contain much organic matter, almost in- 

 variably contain tetanus bacilli, and that latitude, climate, 

 and special meteorological conditions, have far less influence 

 on its development than defective drainage, imperfect hy- 

 gienic conditions, and the degree of cultivation of the soil. 

 It appears, however, that our' methods of cultivation are not 

 yet perfect, for it is an undoubted fact that failures to pro- 

 duce tetanus with pure cultivations are of very common 

 occurrence, even in the hands of those best fitted to carry on 

 experiments of this kind. So markedly is this the case that 



