DIPHTHERIA. 393 



The diphtheria bacillus grows readily upon all the 

 ordinary media, and is a very easy organism to obtain 

 in pure culture. Loffler has shown that the addition 

 of a small amount of glucose to the culture-medium 

 increases the rapidity of the growth, and suggests a 

 special medium which bears his name — Loffler's blood- 

 serum mixture : 



Blood-serum, 3 ; 



Ordinary bouillon + i per cent, of glucose, i. 



This mixture is filled into tubes, coagulated, and steril- 

 ized like blood-serum, and is one of the best-known media 

 in connection with the study of diphtheria. 



The studies of Michel ! have shown that the develop- 

 ment of the culture is much more luxuriant and rapid 

 when horse serum instead of beef or calves' blood is used. 

 Horse's blood can easily be secured by the introduction of 

 a trocar into the jugular vein ; 5 liters of it can be with- 

 drawn without causing the animal any inconvenience or 

 producing symptoms. 



The impossibility of clinically making an accurate di- 

 agnosis of diphtheria without a bacteriologic examination 

 has caused many private physicians and many medical 

 societies and boards of health to equip laboratories where 

 accurate examinations can be made. The method re- 

 quires some apparatus, though a competent bacteriologist 

 can often make shift with a bake-oven, a wash-boiler, 

 and other household furniture instead of the regular 

 sterilizers and incubators, which are expensive. 



When it is desired to make a bacteriologic diagnosis 

 of a suspected case of diphtheria or to secure the bacillus 

 in pure culture, a sterile platinum wire having a small 

 loop at the end, or a swab made by wrapping a little 

 cotton around the end of a piece of wire and carefully 

 sterilizing in a test-tube, is introduced into the throat 

 and touched to the false membrane, after which it is 

 smeared carefully ove* the surface of at least three of 



1 Centralbl.f. Bakt. u. Parasilenk., Sept. 24, 1897, Bd. xxii., Nos. 10 and II. 



