200 APPLIED BACTERIOLOGY 



mediately before use. In the choice of a syringe, it is 

 necessary to select one which can be boiled without 

 damage. The piston should be made of asbestos or india- 

 rubber, and all the joints made tight by washers of the 

 same substances ; no cement of any kind should be used in 

 the joints. If care is not taken, septic troubles may arise. 



In a few instances abscesses have been recorded after 

 injection, and these may be due to two causes : either the 

 injection has not been performed with proper precaution, 

 or the serum has been previously contaminated. The latter 

 can only be avoided by using serum from a thoroughly 

 reliable source, and by taking care not to use serum from a 

 bottle that has been left open and exposed to the air. 



As far as the strength of antitoxin is concerned, we are 

 met with the difficulty that a uniform standard of strength 

 is not always adopted. The testing of the serum is not an 

 easy matter, and can only be performed by a skilled 

 bacteriologist ; but until a uniform standard is adopted, it 

 will be impossible for clinical observers to agree upon the 

 proper dose to be employed in any individual case. 



Injections of serum are often followed by the appearance 

 of various rashes, sometimes erythematous, at other times 

 urticarial, and in a few cases not at all unlike the rash of 

 scarlet-fever or of measles. These rashes usually come on 

 in from seven to ten days after the injection; sometimes the 

 rash is accompanied by more or less pyrexia, and in a small 

 number of cases by pains, and even effusion into some of 

 the joints. There is a good deal of evidence in favour of 

 the idea that local disturbances and erythematous rashes, 

 etc., when they occur, may be in great measure due to the 

 albuminous constituents of a serum ; they may appear even 

 after injection of normal horse serum. It has been alleged 

 by some that the injection of serum has actually been the 

 cause of nephritis, but this is contrary to the experience of 



