404 Contagious Pleuro-pneumonia. 



t 



the incision. The inoculation is carried out by clipping a grooved vaccinating needle 

 into the lymph, and sticking the same about 10 cm. from the point of the tail into 

 the subcutis, or the lymph may be allowed to coagulate in a glass vessel and 1-2 

 drops of the serum are subcutaneously injected into the same place by means of a 

 Pravaz syringe. 



In procuring the virus special care should be taken that the lungs are only 

 affected with characteristic acute changes of pleuro-pneumonia, and that the lymph 

 is very clear and light yellow. Lungs in which necrotic centers are already present 

 must not be used for this purpose, as they frequently contain pyogenic or gangrene 

 producing bacteria. Some filter the collected lymph through pure linen and inoculate 

 the filtrate. If pure serous exudate is present between the layers of the pleura, 

 this may also be utilized for the inoculation. 



The described procedure has repeatedly been modified; thus Martin introduces 

 under the skin of the end of the tail, immediately under the last caudal vertebra a 

 hair cord three mm. broad and 8-10 cm. long saturated with lymph. This is allowed 

 to remain in place for 8 to 12 days and is in the meantime repeatedly moistened with 

 lymph. A similar method is practiced by the Boers in South Africa, in which 

 they saturate raw, woolen threads with lymph . and introduce them under the skin 

 at the point of the tail. Defays, Bouley, Thiernesse and Degive injected 2 cc. of 

 virus directly into a superficial vein, for instance into the jugular. 



Others again, among them Willems, utilize the serous fluid of the swelling at 

 the point of inoculation as vaccine, whereas in Australia, in accordance with 

 Pasteur's suggestion, the fluid of the lung is first inoculated subcutaneously into 

 the dewlap, or behind the shoulder of a calf two or three months old, and from the 

 resulting swelling after the death of the animal the lymph, which sometimes amounts 

 to several liters, is collected in glass tubes, the ends of which are closed by melting. 

 The lymph thus obtained is supposed to remain unchanged and effective for six 

 to eight weeks if kept in a cool place (according to Schmidt adult cattle are still 

 better adapted for lymph production than calves). 



Laquerriere allows the lung to freeze at 5° to 6° below zero, and then places 

 small pieces of it in sterilized glass vessels. The lymph which oozes out has the 

 same effectiveness after one year as when taken out from the fresh lung. Schiitz 

 & Steffen grind the fresh lung juice in a mortar with glycerin and then place it in 

 a cool place. This substance remains effective for at least eight days, as coagulation 

 is prevented by the glycerin. Nocard incises the hepatized lungs, which have been 

 washed in hot water, deeply, and covers the incision with a plate. The collected 

 lymph is drawn off with a sterilized pipette, mixed with water containing carbolic 

 acid and glycerin (1 part lymph, % part of a %% solution carbolic acid, % part 

 pure neutral glycerin). This is filtered through paper and kept in glass tubes in 

 cool dark places. Such lymph remains unchanged for months. The natives ' 

 of Senegambia for a long time employed the method of taking the point of a knife 

 or dagger, dipping it first into the affected lungs, and then sticking it under the 

 skin of the back of the neck of the animal which was to be inoculated. 



Besides the methods described Theiler recommends the administration of viru- 

 lent material (fluid, of the lung or culture) per os, (6 oz. diluted with water), as 

 has been practiced for a long ^ime in- South Africa. The immunity is supposed to 

 last for 18 months. 



II. Immunization with Pure Cultures. In France immun- 

 ization with pure cultures has been carried out since 1899 ac- 

 cording to the suggestion of Nocard & Eoux, and the results 

 have in general been more favorable than with the old method. 

 An eight-day old culture of the virus in Martin's bouillon serves 

 as vaccine, of which cattle receive % to % cc. subcutaneously, 

 inoculated into the tip of the tail. The immunity thus pro- 

 duced lasts for at least two years, as immunized animals, which 

 have distinctly reacted to the inoculation, withstand after two 

 years a subcutaneous injection of 0.5 cc. of pure culture without 

 any reaction (Constant & Mesnard). 



In the beginning of 1901, 2,359 cattle were immunized by this method in 

 Southern France, on 597 premises; of these 3 (0.12%) died, 18 head (0.7%) lost 

 their tails. All of these losses occurred in one township, where a veterinarian had 

 not carried out the inoculation in accordance with the requirements; otherwise no 



