DIRECTIONS FOR THE USE OF BLACK-LEG VACCINE 259 



to be vaccinated receives only the exact dose intended for it. The 

 plunger is made of rubber; it should be air-tight in the glass barrel, 

 and yet capable of being moved up and down smoothly. In order 

 to prevent the plungers and washers from drying out, the small loose 

 cap should be always tightly adjusted to the peg when the syringe 

 is not in use. The hypodermic needles should be kept very sharp at 

 the point, in order to pass easily through the skin, and when not in 

 use should have a fine brass wire passed through each to prevent 

 rusting on the inside. Whenever the point of the needle gets blunt 

 it becomes very difficult to pass it through the skin, causing the fingers 

 of the operator to become sore from attempting to force it through, 

 and frequently the needle either bends or breaks. It is, therefore, 

 of importance to have a small oilstone at hand on which to sharpen 

 the point of the needle. 



Before preparing the vaccine all the utensils, together with the 

 syringe, must be sterilized thoroughly. This is done by putting the 

 mortar, pestle, measuring glass, funnel, and needles in a pan of cold 

 water and placing them over the fire. After boiling for ten minutes 

 the pan with the contents should be allowed to cool off slowly; then 

 remove the utensils from the water and wipe them dry with a clean 

 linen cloth which has been previously boiled. 



Preparation of the Vaccine. Place the contents of one packet of 

 the vaccine in a porcelain mortar and add a few drops of boiled 

 water. Work the powder thoroughly with the pestle and then add, 

 little by little, as many cubic centimeters of water as the packet 

 contains doses. As the syringe contains exactly 5 c.c. it may be 

 used for measuring the water. Place a small piece of absorbent 

 cotton in the funnel and press it lightly into the upper end of the 

 neck, sufficient to keep it in place; moisten the cotton with a few 

 drops of boiled water and let it drip off. Stir the mixture in the 

 mortar thoroughly, and before it has had time to settle, pour it into 

 the funnel under which the measuring glass has been placed. The 

 solution should not be perfectly clear. If this is the case, the cotton 

 has been pressed too closely into the neck of the funnel. 



Age of Animal and Dosage. Calves, as a rule, should not be 

 vaccinated until they are six months old. Under this age they are 

 practically immune, and it has been claimed that when vaccinated 

 before they are six months old they are likely to lose the artificial 

 immunity induced and become susceptible again. Animals over two 

 years old are rarely affected, and the mortality is so small as to make 

 vaccination unprofitable. It is the animals between six months 

 and two years old which should be vaccinated. Vaccination and 

 castration should not be performed at the same time. 



Ten days to two weeks should be allowed to elapse after vacci- 

 nation before any surgical operation is undertaken, and if performed 

 before the vaccination, ample time should be allowed for the part 

 to heal and the animal to regain its lost strength. Animals one year 



