320 PROTECTIVE INOCULATIONS. 



the dose of 2.5 cubic centimetres no reaction occurs. On the other 

 hand, this dose causes an intense febrile reaction in horses with glan- 

 ders. There is a chill followed by an elevation of temperature amount- 

 ing to 2 to 3 C., accompanied by dyspnoea and great debility; in 

 some cases the animal dies as a result of the inoculation. 



For the preparation of the active substance in a dry condition, 

 Foth gives the following directions : The cultures are evaporated at 

 a temperature not exceeding 80 C. to one-tenth of their volume, and 

 filtered. The clear and thick, 'dark-brown liquid is then slowly 

 dropped into absolute alcohol (twenty-five to thirty parts) with con- 

 stant stirring. A flaky, white precipitate is thrown down, and ac- 

 cumulates as a pale yellow mass upon the sides and bottom of the 

 vessel. After standing for twenty-four hours the alcohol is carefully 

 drawn off and the precipitate washed with absolute alcohol. This 

 is to be carefully done, and to avoid loss will require several days. 

 The precipitate is then placed upon a thick paper filter and thor- 

 oughly washed by drawing alcohol through it by means of an exhaus- 

 tion apparatus, after which the purified precipitate is collected and 

 dried with care at a low temperature best in a vacuum over sul- 

 phuric acid. A spongy, crumbling mass is thus obtained, which is 

 easily crushed to form an extremely light white powder. This is 

 readily soluble in water. It is not at all hygroscopic, and can be 

 preserved in a dry condition without difficulty . The dose for a horse 

 is 0.1 gramme. 



De Schweinitz and Kilborne, in a paper published in November, 

 1892, state that in December, 1890, they 



"extracted from culture liquids of the Bacillus malleus an albumose which 

 appeared to be the active principle in these cultures. At that time a pre- 

 liminary experiment was conducted to see if this substance could be used 

 to make guinea-pigs immune to the disease glanders. The result was that 

 out of a set of five, three vaccinated and two checks, only one, a vaccinated 

 animal, recovered from an inoculation of a glanders culture. This experi- 

 ment has since been repeated with sets of ten and twelve guinea-pigs each, 

 with, at present writing, only negative results. A note of this work was 

 published in the ' Annual Report of the Department of Agriculture for 1891.' 

 The albumose was best obtained from the cultures, after the removal of the 

 germ, by means of a Pasteur filter, by precipitation with absolute alcohol, 

 resolution in water, and reprecipitation." 



Babes (1892) claims to have succeeded in immunizing guinea-pigs 

 against glanders by means of the toxic substances contained in cul- 

 tures of the bacillus. 



Foth (1894) has reported the results of extended experiments 

 which have been made with his " Malleinum siccum " in Austro-Hun- 

 gary. These results are stated as follows : 



