30° 
In some cases tetanus is due to irritation of the stomach and intestines, 
caused by worms or collections of sand which have been ingested; and 
sometimes irritation of the womb following abortion is a cause of this dread 
malady. 
Tetanus, when not due to a wound or injury, is generally traceable to 
cold and damp, especially after exhaustion. Horses when clipped are 
sometimes afterwards attacked ; and similarly sheep, when exposed to cold 
and wet immediately after being shorn, not uncommonly manifest the 
symptoms of tetanus. 
It has been observed that lock-jaw is more prevalent in certain districts 
than in others; for in some parts of the country it is very frequently met 
with, while in others it is as rarely seen. In Lincolnshire it is fairly 
common. Sometimes it occurs as a local disease, and Professor Williams 
records that in the summer of 1858, he witnessed ten cases in a fortnight, 
and of these some were due to injuries, while the others where not 
traceable to wounds of any kind. In the human species it has been noticed 
that tetanus is very common in the tropics, apart from any injury. As to the. 
real nature of tetanus there is some doubt. Some hold the traumatic form 
to be due to irritation of the nerves implicated in the wound, and think that 
the spasms result in consequence thereof. In support of this it has been 
argued that many cases of lock-jaw following docking have recovered after 
repeating the operation higher up. Yet it must nevertheless be remembered 
that recovery does not invariably follow the repetition of the operation, and 
moreover, some very mild cases of traumatic tetanus recover without any 
treatment whatever, 
We are of the same opinion with those who view tetanus as a blood 
-disease, and several reasons can be advanced in support of this theory. 
Firstly, we have seen that tetanus often occurs without any injury. 
Secondly, tetanus is more prevalent in certain districts than in others, and 
is sometimes localised to certain parts of the country, affecting several 
animals at once. There is, however, no proof that tetanus is ever 
contagious. Thirdly, the resemblance of this disease to rabies or 
hydrophobia, which has been shown by that eminent pathologist, M. Pasteur, 
to be due to certain low forms of vegetable life, suggests a similarity in the 
nature of the cause. Lastly, tetanus is said to be transmissible to man if 
the flesh of animals which have died of this disease be partaken of. This 
‘statement requires confirmation. 
Tetanus may be acute or chronic, and there are also several varieties 
which have received various names from the particular muscles mainly 
involved. 
When lock-jaw owes its origin to a wound, it usually manifests itself in 
from Io to 28 days after the infliction of the injury, or it may occur even at 
.an earlier date than this. Generally a stiffness about the neck and lower 
jaw and of the muscles near the seat of injury is first noticeable. There is 
difficulty in mastication and swallowing, together with increase of the saliva 
and a peculiar champing of the teeth. Ifthe head be suddenly elevated, or the 
