CHAPTER VII. 
BACTERIA CAUSING ACUTE INFECTIONS. 
The Bacillus of Tetanus. 
Tetanus, or lockjaw, as it is more commonly 
called, has existed for many centuries, but the micro¬ 
organism causing the infection was not discovered 
until 1885, when Nicolaier, a German bacteriologist, 
was successful in producing the disease in animals by 
injecting them with small amounts of soil. 
Morphoi- The organism is a bacillus of large size, which 
forms spores readily. It grows on the ordinary cul¬ 
ture media, but only when no oxygen is present. The 
spores are located at one end of the bacillus, and cause 
a swelling which gives it much the same shape as a 
drumstick. The spores are very resistant to harmful 
influences. They will survive dry heat of 8o° C. for 
an hour and 5 per cent, carbolic acid solution for 
twelve to fifteen hours. Away from sunlight the 
spores may live for years. 
Its natural home is the soil, especially where it 
has been cultivated and manured. This is due to the 
fact that tetanus bacilli are present in the intestines of 
some animals. In the United States the soil in the 
Hudson Valley and on Long Island seems particularly 
infectious. 
♦ Infection generally occurs by the contamination 
( 74 ) 
