274 A MANUAL OF BACTERIOLOGY 



the writer x found diphtheria-like bacilli in 58 out of 385 

 children (15 per cent.) admitted into the Victoria Hospital, 

 Chelsea. 



Ford Robertson believes that diphtheroid organisms 

 possibly the Klebs-Loffler bacillus itself may play an 

 important part in the production of general paralysis of 

 the insane. His views have not gained general 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. diphtheria 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. 208). 

 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. diphtheria, but on Ehrlich's side- 

 chain hypothesis it seems more likely that in such cases 

 there happens to be an excess of the receptors which 

 constitute antitoxin naturally free in the blood. 



Guinea-pigs are the animals generally employed for 

 experimental work on diphtheroid organisms. In order 

 to compare the effects and virulence of various bacilli it 

 is customary to make the inoculation with a measured 

 volume of a forty-eight hours' broth culture. From Ol 

 c.c. to 2 c.c. of such a culture, according to the virulence, 

 inoculated subcutaneously, is usually required to kill a 

 250-grm. guinea-pig within three days. At the seat of 

 inoculation hsemorrhagic oedema forms, haemorrhages 

 occur in the serous membranes, and especially in the 



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

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



