202 



If a second guinea-pig is injected with toxin and diphtheria 

 antitoxin at the same time and if it is found that this guinea- 

 pig remains without any symptoms, as another, being injected 

 with taxin only, dies or gets some local reaction, it is proved 

 with centainty, that the culture which produced the toxin is 

 one of true diphtheria bacilli. 



So we find in this a method to make out with certainty if 

 a given culture consists of real diphteria bacilli, but to my mind 

 we must not conclude from the absence of a toxin harmful to 

 guinea-pigs that the culture is not one of diphtheria. 



I have now given you an outline of the principal methods 

 which may be used by the examination of diphtheria ; to wind up 

 with I should like to mention the following : Give a culture to 

 an experimenter trained in this part of bacteriology, put at 

 his disposal a well-equipped laboratory and above all sufficient 

 time, he will in most cases be able, though it may be after 

 many weeks, to tell you with great probability if the culture 

 you gave him was diphtheria or not. 



But if we face the practical side of the question another 

 problem crops up, as one of the provisions made, namely that 

 of having plenty of time, fails here completely. A result 

 obtained after weeks or months is hardly ever of any use to 

 the answering of questions that face us in practice. What we 

 want here is to know in the shortest time possible, if a person 

 has diphtheria bacilli in his throat, nose or other part of his body. 



In most cases the answer to this question cannot be given 

 with absolute centainty in a short time, therefore we try to 

 get as near to the truth as possible and all sorts of experiments 

 are made to improve the working-methods. 



In the Central Laboratory we have organised the diphtheria 

 examination as follows : The medical man receives a wooden 

 box containing two testtubes, in one of which there is a 

 sterile swab of cottonwool ; the other is a sloped tube of 

 LOEFFLER 'S serum . The practitioner rubs the mucous membrane 

 of the patient with the swab and after that he rubs it over 

 the serum. As soon as possible all this is sent to the Central 

 Laboratory and on arriving there the swab is brushed over the 

 surface of a Petri dish containing LOEFFLER 'S serum. Both 

 culture media, testtube and plate, are now incubated at 37" C. 



