364 RABIES, VACCINIA AND THE FILTERABLE VIRUSES 



the section is pink, then quickly differentiate in acid alcohol (i drop 50% acetic 

 acid in 30 c.c. absolute alcohol) until a slight blue outline to the ganglion cells is 

 obtained. Treat rapidly with absolute alcohol and xylol and mount in balsam. 

 The Negri bodies show as light carmine pink bodies on the light blue ground of the 

 gangh'on cells. In the interior of the pink bodies dark blue dots or rings may be 

 observed. 



This method can also be used for brain smears. 



In addition to examining for the Negri bodies, a rabbit may be inoculated 

 subdurally with a sterile salt-solution emulsion of the medulla of the dead dog. 



If the brain and medulla of the dog are to be sent to a laboratory 

 for examination they should be packed in ice or placed in glycerine. 

 Take of glycerine one part and one part water. Sterilize the diluted 

 glycerine by boiling, allow to cool, and drop the pieces of brain tissue 

 into this. This does not kill the virus. 



When from advanced putrefaction, or otherwise, the Negri bodies cannot be 

 found the changes in the Gasserian ganglia may give a diagnosis. In typical lesions 

 the ganglion cells are more or less completely destroyed and replaced by cells of 

 other types. 



When a person is bitten by a dog suspected of being rabid the following 

 simple measures should be instituted. The dog should be kept under observation 

 in a safe quiet place and will show clinical evidence of rabies within five days and 

 will die shortly afterward in case rabies exists. When the animal dies the head 

 and several inches of the neck should be removed and packed in ice and sent to the 

 nearest laboratory. 



Antirabic serum has been prepared by injecting sheep with emulsions of rabbits' 

 cord and brain at first intravenously, then subcutaneously. 



The thorough cauterization of the dog-bite wound with pure nitric 

 acid, as soon as possible after the bite, is imperative even when the Pas- 

 teur treatment can be given later. 



VACCINIA is a disease produced artifically by the injection of vaccine virus ob- 

 tained from the calf. The material for vaccine is taken from vesicles about 

 one week after the inoculation. The most potent material is in the pulp at the base 

 of the vesicle and not in the lymph which exudes from the vesicle. The pulp is 

 ground up and mixed with an equal amount of glycerine, which acts not only as a 

 preservative but as a mild antiseptic for nonsporing bacteria. The calves are autop- 

 sied after the pulp has been curetted from the inoculated skin of the abdomen to be 

 sure that no disease exists in the calves. The virus is afterward tested for pus organ- 

 ' isms, tetanus, and foot and mouth disease. 



Guarnieri in 1892 first observed small bodies near the nucleus of infected epi- 

 thelial cells, He called them Cytoryctes vacciniae. Calkins regards these bodies 

 as well as the Negri bodies as being rhizopods and the distributed chromatin as 

 idiochromidia (granules of nuclear chromatin within the cytoplasm). 



