HYDROPHOBIA. 319 



fever advances a rambling delirium supervenes ; the thirst 

 increases, but along with this there is great difficulty in 

 swallowing — especially fluids — and after making one or 

 two attempts to swallow, the very sight of water suggests 

 such horrors that thirsty as the patient is, he is anxious to 

 avoid it. Then muscular tremors are noted, these become 

 more and more marked and violent spasms are easily 

 stimulated as in tetanus. A sharp sound, a touch, a bright 

 Ught, or even a breath of air, may give rise to violent muscular 

 convulsions, and eventually the patient is slowly suffocated 

 as in tetanus. One can well imagine that to a man of 

 Pasteur's temperament and mode of thought such a terrible 

 disease as that, the symptoms of which I have just sketched, 

 would just be the subject that would fascinate him. Here was 

 a problem surrounded by difficulty but of such a character 

 that the very difficulties invited success ; whilst if success 

 were attained he would have the satisfaction of feeling that 

 he had done something more to alleviate human suffering — 

 more even than he had already accomplished ; hence the 

 preliminary experiments we have already mentioned. In 

 order to convince himself that the disease which he had 

 produced in the rabbit was really hydrophobia he must 

 obtain the poison in a perfectly pure condition ; as he had 

 already found that Galtier's experiments as regards the blood 

 of rabid animals were incorrect, he determined to repeat the 

 same experiments with fluid taken from the cavities of the 

 brain and spinal cord ; here again he was successful, for 

 although Galtier had been unable to produce the disease 

 with such fluid, Pasteur found that by taking a few drops of 

 the cerebro-spinal fluid and introducing it under the outer 

 membrane of the brain (chloroforming a rabbit and removing 

 a small round disc of bone from the skull cap, then replacing 

 the bone and stitching up the wound, which healed almost 

 immediately) hydrophobic symptoms were rapidly developed. 

 This fluid from the central nervous system of a hydro- 

 phobic rabbit contained no septic organisms, and as the 

 disease was rather more slowly developed after the inocu- 

 lation of such virus (although it could be induced with 

 absolute certainty) than when saliva was used, he discontinued 

 the use of the latter, the inoculations being now made from 

 animal to animal and always with the cerebro-spinal fluid. 

 Fragments of the brain and spinal cord introduced under the 



