NON-SPORING BACILLI 249 



more than the incubation period of the serum disease 

 (that is, ten to twelve days) before. On account of these 

 facts, Goodall advises that prophylactic doses of diphtheria 

 antitoxin should not be given to anyone without discrimina- 

 tion, and never to a person the subject of asthma (see 

 page 213) . In an actual attack of diphtheria in such a person 

 the risk would have to be definitely considered, and a 

 judgment come to on the relative dangers of the attack 

 and the use of the antitoxin. In those who have had a 

 previous dose, either for an attack or for prophylaxis, some 

 time antecedent, one should be on the outlook for alarming 

 symptoms if a second dose is being given. It is stated 

 that so far no death has been recorded in these 

 circumstances, which is to some extent reassuring. This 

 class of case suggests the avoidance of prophylactic doses 

 altogether, as if the person takes an attack more than 

 ten days later, he is sensibilized to the now required 

 injection. (See for further details, articles by Goodall in 

 Public Health, January, 191 1, and in Encyclopedia Medica ; 

 and by Currie, Journal of Hygiene, January, 1907. Also 

 annotation in Lancet, 1911, vol. i, page 1654.) 



Antitoxic serum keeps well in a cool, dark place. 

 Anderson has found that at 20 C. the average yearly loss 

 of potency is 20 per cent ; at 15 C, it is about 10 per cent ; 

 and at 5 C, it is only about 6 per cent. Dried, and kept 

 at 5 C, its potency was practically unimpaired after 5-5 

 years. The addition of chloroform, tricresol, etc., to 

 preserve, had no influence apparently on the rate of 

 deterioration. 



