322 PROTECTIVE INOCULATIONS. 



and sterilized for an hour in a steam sterilizer. This liquid remains 

 sterile on account of the presence of mercuric chloride, and may be 

 preserved a long time without losing its activity. The dose is from 

 0.3 to 0.5 cubic centimetre, which is diluted to three cubic centimetres 

 with carbolic acid water (0.5-per-cent solution). The diluted solu- 

 tion may also be kept a long time without losing its activity. 



Bonome and Vivaldi (1892) have tested the action of mallein ob- 

 tained by precipitation with alcohol upon various animals. Guinea- 

 pigs were found to resist comparatively large doses (ten to fifteen 

 milligrammes), while rabbits and cats were more sensitive to the 

 toxic action. In guinea-pigs and rabbits infected with glanders ba- 

 cilli very small doses had a favorable influence upon the progress of 

 the infection, and in healthy guinea-pigs a certain degree of immunity 

 was induced by the repeated injection of small doses. 



In a subsequent paper (1894) Bonome reports that he has had 

 favorable results in the treatment of chronic glanders in man by doses 

 of yV to ^ cubic centimetre. The first dose is said to have caused 

 an elevation of temperature, headache, polyuria, etc., but upon re- 

 peating the dose after two or three days a decided improvement of 

 the general symptoms followed. 



Chenot and Picq (1892) claim to have cured glanders in guinea-pigs 

 by injections of blood serum from the ox, which animal has an im- 

 munity from the disease. They also state that the blood serum of 

 the ox is germicidal for the glanders bacillus. Guinea-pigs treated 

 with ox serum, either before or after infection, recovered in seven 

 cases out of ten. When inoculated with very virulent cultures, which 

 usually killed these animals in five days, the animals are said to have 

 survived from twenty-one to forty-two days. 



Bonome (1894) reports his success in curing infected guinea-pigs 

 by means of filtered cultures made in the blood serum of the ox. He 

 was not, however, successful in accomplishing this result with mallein 

 made in the usual way. 



HOG CHOLERA. 



The experiments thus far made with reference to protective inocu- 

 lations against hog cholera have not given very satisfactory results. 

 Selander and Metchnikoff have reported success in immunizing rab- 

 bits, but according to Smith their experiments were made with the 

 bacillus of swine plague, and not with that of hog cholera as they 

 supposed. The following conclusions have been formulated by Smith 

 as a result of his extended experiments : 



"1. It is possible to produce immunity toward hog-cholera and swine- 



