RABIES 179 



needle can be used, but the risk of sticking the hand is lessened if 

 the needle has a fixed handle, the other extremity terminating in a 

 spear with a slit in its side, which is opened and closed by pushing 

 a button. It is passed through the skin closed, then opened, the 

 thread inserted, when it is again closed and withdrawn. Of course, 

 all the materials and instruments have been sterilized, and during 

 the operation are placed in a pan of 3 per cent, carbolic acid. The 

 rabbit is then placed in a box properly labelled. Wire cages are 

 generally used, but if the floor be of asphalt or of cement, a box 

 without a bottom, having a wire grating for a lid, with a bed of 

 saw r dust or straw, is more convenient to keep clean. 



"In an institute like the one at Baltimore, where approximately 

 120 cases are treated annually, two animals are daily inoculated, 

 the material for this purpose being obtained from the medulla of 

 those animals which have died of rabies during the day or the night 

 preceding. To this end a piece from the floor of the fourth ventricle, 

 measuring about 2 cm. in length, is rubbed up in 1 c.c. of bouillon, 

 and of this emulsion, as I have just stated, three or four drops are 

 injected beneath the dura. 



"As I have mentioned before, rabbits that have been inoculated 

 with virus fixe develop rabies after an incubation period of from 

 six to eight days (the shortest period being usually only reached 

 after ninety pasages), and then die almost four days later, viz., 

 after ten to twelve days following the inoculation. The dead 

 animals, as soon after death as possible, are sprayed with lysol or 

 bichloride and stripped of their fur, when the cord and brain are 

 removed under aseptic precautions. The cord is severed just below 

 the medulla and divided into two equal pieces, which are sus- 

 pended by sterilized silk threads in a sterile glass jar (aspiration or 

 irrigation bottles, 1 liter capacity), the bottom of which has been 

 covered about 2 cm. deep with flake caustic potash. The threads 

 are held in position by the cotton stopper and are allowed to hang 

 outside. The medulla is kept in a sterile dish and is used to continue 

 the series of inoculations, as indicated above. The jars are labelled 

 with the date, the number of the passage, and the number of the 

 animal passage. A post mortem finally is performed and any cord 

 rejected in which the animal is found diseased, or in which bacterio- 

 logical examination of the cord has shown the presence of pyogenic 



