X 



Negri Bodies, Patliogeuieity. 467 



80° CBertarelli). The vims is scarcely influenced by severe cold ( — 16° — 3o°C.). 

 Putrefaction destroys the virus only after long exposure; for instance Galtier 

 found that the medulla of a dog that had been buried for 44 days was still virulent, 

 Eatz reported virulence persisting after exposure to putrefaction for 14 to 24 days, 

 while Klimmer found the cord of a rabbit to remain virulent which had been 

 undergoing putrefaction for 15 days. Of the chemical agents, glycerin acts rather 

 as a preservative, for according to Kempner the medulla retained its virulence in 

 glycerin for at least 8 to 10 days; according to Rodet & Galavielle for 10 months. 

 On the other hand the virus is destroyed in a few minutes when exposed to the 

 action of each of the following: Mercuric chloride 1:1000 (Celli), diluted chlorine 

 or bromine water (10-20 drops of the official chlorine or bromine water to 10 cc. 

 of water), 1% solution of potassium permanganate, and 2% sulphuric acid 

 (Bokay & Szilag-yi), 5% hydrochloric acid, 1% creolin solution and also to lemon 

 juice (Blasi & Traveli). The natural gastric juice destroys the virus of rabies 

 in 41/^ to 5 hours (Babes & Talasescu), and bile kills it in several minutes. In a 

 vacuum from which the sunlight has been excluded the dried and pulverized brain 

 substance will remain virulent at least 9 months (Vansteenberghe). 



The Negri bodies are destroyed by weak alkaline solutions; they are however 

 very resistant to the action of mineral acids (Negri) and are only imperceptibly 

 altered by drying, warmth, putrefaction, glycerin ami water (Bertarelli & Daddi). 



Pathogenicity. By tlie inoculation of virulent saliva or 

 oblongata emulsion the disease may be transmitted to dogs, 

 cats, guinea pigs, rabbits, mice, rats and also to other mammals. 

 The best results are obtained by the injection of the virus under 

 the dura mater of brain or cord, into the brain substance, into 

 the anterior chamber of the eye, or into the muscles. Equally 

 good results may be obtained by injection into the peripheral 

 nerves. Rubbing the virus into the scarified skin of dogs and 

 rabbits is successful in only 50% of the cases. Subcutaneous 

 inoculation in dogs rarely gives positive results. In rabbits 

 75% of subcutaneous injections are successful only when the 

 muscles or the nerves have been injured at the same time. 

 Intravenous injection sometimes produces the disease in dogs 

 and rabbits, but not in ruminants or horses. 



Konradi has infected rabbits through the scarified skin, Galtier 

 through the shaved skin, Hogyes, Galtier, and Remlinger through the 

 uninjured nasal mucous membrane, and Galtier and Conte through 

 the conjunctiva, while an infection of the mucous membrane of the 

 vagina only succeeded in exceptional cases. Several experiments have 

 been conducted without results by feeding saliva, meat, and spinal 

 cord of rabid animals to horses, dogs and sheep (Delafond, Renault, 

 Hertwig, Nocard). Nocard in the course of 2 months, had a fox eat 

 the cerebral and spinal tissue of 6 rabid foxes and 12 mad dogs, the 

 unusual feed not having the slightest harmful effect. 



Birds may he infected artificially, but they are not very receptive, 

 and the virulence of the virus seems to decrease in their bodies (Gibier, 

 Lote). Cold-blooded animals are also killed by the rabies virus, and 

 frogs succumb with paralytic symptoms. 



In rabbits which have been infected successfully, the disease de- 

 velops in its paralytic form, as a rule the hind parts and exceptionally 

 the front part of the body becoming paralyzed first. The paralysis soon 

 becomes general, spasms in some groups of muscles are observed, and 

 at last the greatly emaciated animal dies in the course of 2 to 3 days. 

 Indications of excitement (unrest, desire to bite) are seldom observed, 

 but these symptoms have been often observed in guinea pigs. In 

 dogs the usual symptoms of rabies develop after inoculation and if 



