PROTECTIVE INOCULATIONS. 335 



" Applicability at any time during 1 the period of incubation up to the 

 moment of the appearance of symptoms of rabies ; absolute absence of viru- 

 lence and of any injurious action : very rapid treatment by the injection of 

 one or several small doses of material : complete solubility and consequently 

 prompt absorption of the material injected and its easy preservation in a dry 

 condition.*' 



INFLUENZA. 



The bacillus discovered by Pfeiffer, in 1892, is now well estab- 

 lished as the specific cause of this disease. Bruschettini has recently 

 (1893) reported the details of his experiments upon rabbits, for which 

 animals this bacillus is pathogenic. As a result of these experiments 

 he has reached the following conclusions : 



" 1. Eabbits may be vaccinated against the pathogenic action of cultures 

 of the influenza bacillus without great difficulty. 



"2. The best material for producing a high grade of immunity is blood 

 cultures which have been filtered through the Berkenfeld filter. 



"3. The blood serum of immunized animals has strong antitoxic proper- 

 ties, but has no germicidal power. 



"4. The serum of vaccinated animals has the power of conferring im- 

 munity upon other animals, in comparatively small amounts in the pro- 

 portion of 1 : 42,000 of body weight, and perhaps still less. 



"5. This serum has also a decided curative action, and rescues rabbits 

 from death even as late as forty-eight hours after infection by injection of a 

 culture of the bacillus into the trachea." 



These results lead the author to hope that serum-therapy may 

 afford a method of curing this disease in man. For this purpose the 

 blood of an immune rabbit would appear to be the most promising 

 source from which to procure an antitoxic serum. 



INFLUENZA IN HORSES. 



SCHUTZ (1887) has described a minute oval bacillus, usually asso- 

 ciated in pairs, which appears to be the specific infectious agent in 

 the disease known in Germany as Brusteeuche. This bacillus is path- 

 ogenic for mice, rabbits, pigeons, and guinea-pigs, but not for swine 

 or chickens. By injection of cultures into the parenchyma of the 

 lungs Schiitz reproduced the disease confirmed in 1888 by Hell. 



Horses which have suffered an attack of infectious influenza are 

 subsequently immune, and the experiments of Hell have shown that 

 an immunity also follows the disease which results from inoculations 

 with pure cultures of the Schiitz bacillus. 



The extended experiments made by the War Department of the 

 German Government show that the disease is not produced by intra- 

 venous injections or by the ingestion of the bacillus with the food. 

 Infection occurs, however, when cultures are injected into the re- 



