1434 



PLAGUE 



certainty, as well as other insects. One gallon of the lo per cent, 

 solution is sufficient to disinfect a room 12 by 12 in a few minutes; 

 the solution may be washed out afterwards with water. Tobacco 

 and infusions of tobacco will also be found useful, as first demon- 

 strated by Castellani and Low when studying the prophylactic 

 measures to be taken against Pulex penetrans infections in Africa. 



Personal Prophylaxis. — Ever since the middle of the eighteenth 

 century there has been an idea that a vaccine should be obtained 

 for the purpose of protecting the individual. Weszpremi and, 

 later, Samoilowitz and Cerutti tried artificial inoculation, but the 

 results were by no means satisfactory, persons dying from plague 

 as the result of the inoculation. Recently a number of vaccines 

 have been prepared for the purpose of personal prophylaxis, which 

 may be classified into: (i) Vaccines composed solely of the chemical 

 products of the bacilli; (2) vaccines composed of chemical products 

 and dead bacilli; (3) vaccines composed of living attenuated bacilli; 

 (4) polivaccines. 



Chemical Vaccines. — In 1897 Lustig and Galeotti prepared a 

 plague vaccine, composed of the nucleo-proteids of the bacilli 

 obtained by shaking agar cultures with i per cent, caustic potash 

 solution, and after two hours adding 0-5 per cent, acetic acid, 

 and thus obtaining a precipitate of nucleo-proteids. It is adminis- 

 tered by subcutaneous or intramuscular injections in doses of from 

 2 to 3 milligrammes. This method has been adopted in La Plata 

 with success, and has been experimentally supported by Rowland. 



Vaccines composed of Chemical Products and Dead Bacilli.- — ^The 

 most important is Haffkine's plague prophylactic, prepared by 

 growing the bacillus for four to six weeks in broth, and then 

 sterilizing at 65° to 70° C. for one hour, and then decanting into 

 bottles, with or without the addition of a little carbolic acid. The 

 dose for an adult man is 3 c.c, for an adult woman 2 to 2I c.c, and 

 children in proportion to their age (or size). The injection is made 

 subcutaneously into the arm or loin under strict antiseptic pre- 

 cautions. Three or four hours after inoculation the temperature 

 rises, and in twelve hours reaches 102° to 103° F., while tenderness 

 and swelling may occur at the site of the inoculation, and malaise 

 and general discomfort be felt, which disappear in one to two days, 

 and the swelling in about a week or so. There is no doubt of the 

 benefit of this prophylactic, which gives protection for a considerable 

 number of weeks, and perhaps months, as shown by Haffkine and 

 Simpson. Haffkine considers that the active principle lies in the 

 liquid, but it appears more likely that it is in the dead bacilli. 

 Haffkine's vaccine has been very extensively used in India and other 

 countries since several years, and on the whole has given extremely 

 good results. 



The German Plague Commission used a growth of the bacilli on 

 agar killed by heating to 65° C, and then suspended in normal 

 saline, to which 0-5 per cent, carbolic acid was added. 



Terni and Bandi used the sterilized exudate from the peritoneum 



