INFECTION OP TISSUES 141 



it may be kept in a large bottle on a wall bracket and 

 drawn off as required by a syphon tube provided with a 

 tap or spring clip. The most generally used antiseptics 

 are 5 per cent, carbolic and 1-500 corrosive sublimate, 

 but 2 per cent, cyllin or kerol or, particularly for sporing 

 organisms, 5 per cent, bacterol, is more efficient. The 

 access of flies to the carcase must also be prevented, 

 as they might carry infection. When finished with, the 

 carcase should be efficiently disinfected and disposed of 

 without delay, preferably by burning it, together with 

 the board on which it has been pinned out. 



If the carcase be left, especially in warm weather, for 

 even a few hours before the examination is carried out, 

 the tissues are liable to become invaded and infected by 

 organisms from the respiratory and digestive tracts. In 

 the post-mortem room infection of the tissues is very 

 common, and Ford states that bacteria are frequently 

 present in the organs of normal animals, killed and imme- 

 diately examined (in sixty-nine organs out of ninety-six 

 examined from thirty-four animals). 1 



When the blood of an animal is required several ex- 

 pedients may be adopted. From large animals, like the 

 horse, sheep, and goat, it may be obtained by passing a 

 hollow needle into the external jugular vein (which runs 

 superficially on either side of the under part of the neck) 

 and allowing the blood to drip into a test-tube or flask. 

 In the case of small animals not again needed, the animal 

 may be decapitated or the throat may be cut, and the 

 blood collected in a porcelain dish ; but if a sample only 

 is wanted, and the animal has to be further treated, as 

 in immunity work, it is generally possible to bleed from a 

 superficial vein. In the guinea-pig the needle of a syringe 

 may be passed into the heart and 2-3 c.c. of blood with- 

 drawn without injury to the animal : smaller quantities 



1 Journ. of Hygiene, vol. i, No. 2, 1901, p. 277. 



