DISEASES OF THE NERVOUS SYSTEM. 129 



badly treated, the disease may set in at any time. In one case of 

 which the writer has knowledge the animal was attacked fonr months 

 after receiving the wound in the foot. 



Operations (as well as accidental wounds) may be followed by teta- 

 nus. However, it is not now so common a sequel to operations as it 

 formerly was, for the reason that careful veterinarians use antiseptic 

 precautions as much as possible. 



It has perhaps followed castration oftener than any other operation, 

 due no doubt, in the great majority of instances, to uncleanliness both 

 in regard to the instruments used and to the hands of the operator, as 

 well as the manner of operating. But of course it may follow the 

 operation in some instances when care has been taken in respect to 

 cleanliness. In such cases the cause gains access to the wound after 

 the operation has been performed. 



In an instance of which the writer has knowledge the ordinary 

 operation of tapping for tympany ("wind colic ") was followed by lock- 

 jaw. In this case certainly the disease could not have been due to the 

 instrument, as it was thoroughly clean and had been immersed in a 

 solution of carbolic acid in water (1 to 20) before the operation. It is 

 evident that the cause of tetanus must have either been on the skin at 

 the time of the puncture, and forced into the wound by the instrument, 

 or else it gained access some time afterwards. 



There can be no question that a wound has much to do with the cause 

 of tetanus, but nevertheless the most serious or the most trivial wound 

 can not in itself produce the affection. Something of a specific nature 

 must gain access to the wound for the characteristic symptoms of te- 

 tanus to be developed. Long ago, before a germ having this specific 

 property was discovered, many scientific veterinarians and physicians 

 believed in the infectious nature of the disease. Cases frequently oc- 

 curred in the practice of individual members of the profession that left 

 in > doubt in their minds, and consequently, when it was announced 

 that a microbe had been found in wounds of persons suffering with the 

 disease, that would cause the affection in animals when inoculated with 

 the pus containing the microbes, many points which had been clouded 

 in mystery were at once made clear. (See Plate xxix, Fig. 5.) 



Since this discovery in 1884 many successful experiments have been 

 performed to verify the fact. The same microl>e has been discovered 

 in earth, and cultivations made from it and injected into animals have 

 produced the disease. It has been found in dirt taken from floors, 

 gardens, yards, fields, streets, and animals inoculated with it have 

 developed the disease. Hence there is not much doubt at present con- 

 coming the cause of tetanus, although there are still some eminent 

 practitioners in both the veterinary and medical professions who refuse 

 to receive the results of the numerous experiments as conclusive. 



The evidence so far goes to prove that tetanus is the same disease in 

 111:111 mid animals, ind therefore it is well to bear in mind when attend- 

 24097 9 



