CHAPTER XXII. 
THE BACILLUS OF TETANUS. 
In 1884, Nicolaier, a student in Fliigge’s Institute, 
produced tetanus in mice and rabbits by the subcutaneous 
inoculation of particles of garden earth, and showed that 
the disease was transmissible by inoculation from these 
animals to others. Carle and Rattone, in 1884, demon- 
strated the infectious nature of tetanus as it occurs in 
man. Finally, Kitasato, in 1889, obtained the bacillus 
of tetanus in pure culture and described his method of 
obtaining it and its biological characters. 
The tetanus bacillus occurs in nature as a common 
inhabitant of the soil, at least in places where manure 
has been thrown, being abundant in many localities, 
not only in the superficial layers, but also at the depth 
of several feet. It has been found in many different 
substances and places—in hay-dust, in horse and cow 
manure, in the mortar of old masonry, in the dust from 
horses’ hair, in the dust in rooms of houses, barracks, 
and hospitals, in the air, and in the arrow poison of 
certain savages in the New Hebrides, who obtained it 
by smearing the arrow-heads with dirt from crab holes 
in the swamps. 
Morphology. Motile, slender rods, with rounded ends, 
0.3y to 0.54 in diameter by 2 to 4p in length, usually 
occurring singly, but, especially in old cultures, often 
growing in long threads. They form round spores, 
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