622 HYDROPHOBIA 



bistoury, and the hippocampus will be recognised as the laterally arched 

 ridge which forms the floor of the ventricle. This may be transversely 

 incised and parts removed for the making of smears and sections (p. 615). 



In addition to microscopic examination, a small piece of the medulla or 

 cord of the suspected animal must be taken, with all aseptic precautions, 

 rubbed up in a little sterile - 75 per cent, sodium chloride solution, and 

 injected by means of a syringe beneath the dura mater of a rabbit, the 

 latter having been trephined over the cerebrum by means of the small 

 trephine which is made for the purpose. In rabies in the rabbit, 

 symptoms of paresis usually occur in from six to twenty-three days and 

 death in fifteen to twenty-five days. When the material for inoculation 

 'has to be sent any distance, this is best effected by packing the head of 

 the animal in ice. The virulence of organs is not lost, however, if they 

 are simply placed in glycerin in well-stoppered bottles. 



(2) Treatment. — Every wound inflicted by a rabid animal ought to be 

 cauterised with the actual cautery as soon as possible. By such treatment 

 the incubation period will at any rate be lengthened, and therefore there 

 will be better opportunity for the Pasteur inoculation method being 

 efficacious. The person ought then to be sent to the nearest Pasteur 

 Institute for treatment. It is of great importance that in such a case the 

 nervous system of the animal should also be sent, in order that the 

 diagnosis may be certainly verified. 



Addendum to Appendices A and B. 



The scientific investigation of smallpox and rabies has shown, 

 on the one hand, that it is impossible to associate the conditions 

 with organisms belonging to any well-recognised group. On the 

 other hand, much controversy has in each case been aroused 

 regarding the interpretation to be put on peculiar changes seen 

 in certain tissue cells. The situation is further complicated by 

 the fact that in both diseases the causal agent can pass through 

 a ■ coarse earthenware filter and must therefore be extremely 

 minute. Similar changes in cells and similar facts regarding 

 the minuteness of the causal agents have raised like difficulties 

 in other diseases, such as trachoma and molluscum contagiosum 

 in man, foot-and-mouth disease in cattle, and in the diphtheria 

 and epithelioma contagiosum of birds ; by many, measles and 

 scarlet fever are included in this group. In all the cellular 

 changes described in these conditions, a common feature is the 

 presence in the protoplasm of small chromatic granules often in 

 groups. In recent years these have acquired new importance 

 from the fact that Prowazek, using the highest microscopic 

 powers, observed similar bodies occurring in infective exudates 

 and of sufficient minuteness to pass through a coarse filter. 

 Appearances have been seen in these particles which suggest 

 multiplication. This takes place not by a simple fission as in 

 the bacteria, but by the particle assuming a dumb-bell shape, 



