THE SCHICK TEST 329 



examined. Murray and the writer 1 found diphtheria- like 

 bacilli in 58 out of 385 children (15 per cent.) admitted 

 into the Victoria Hospital, Chelsea. Among immediate 

 contacts the percentage who are carriers is greater 

 36-37 per cent. 



Ford Robertson stated that diphtheroid organisms 

 possibly the Klebs-Loffler bacillus itself play an impor- 

 tant part in the production of general paralysis of the 

 insane. His views have not gained acceptance, and 

 Eyre (loc. cit.) found that the percentage incidence of all 

 diphtheroid organisms and of the Klebs-Loffler bacillus 

 in the throats of the insane was not greater than in well 

 persons, and was unable to isolate the B. diphtherice 

 post-mortem from cases of general paralysis. 



Traces of antitoxin can be detected in the blood after 

 an attack of diphtheria, usually at the end of the first 

 week of convalescence : this antitoxin has probably 

 little to do with the actual recovery from the disease 

 (see p. 254). A small amount of antitoxin has also been 

 occasionally found in well people and in untreated horses. 

 It has been suggested that in such cases there has been a 

 latent infection with the B. diphtherice, but on Ehrlich's 

 side-chain hypothesis it seems more likely that in such 

 cases an excess of the receptors which constitute antitoxin 

 happens to be naturally free in the blood. 



By the Schick test (see p. 352) it has been shown that 

 a majority of infants up to two years of age have a con- 

 siderable content of anti-bodies in their blood, hence 

 their comparative insusceptibility to diphtheria, while 

 children between 2 and 5 years of age have much 

 less ; adults generally have a high content of anti- 

 bodies. Diphtheria carriers, who are simply carriers 

 and not cases of diphtheria, may give a negative 



1 Brit. Med. Journ., 1901, vol. i, p. 1474. See also Graham-Smith, Journ. 

 of Hygiene, vol. iii, 1903, p. 216. 



