276 



For the preparation of a crude butyl-alcoholic fermentation crushed corn *) of 

 Hordeum vulgar e nudum may be used; a pap of potatoes infected with soil and heated 

 not higher than 80 to 85 C. will also do; addition of chalk is not necessary, the 

 butyl bacteria producing no acid. Of course the spores of butyric-acid ferments are 

 si ill present in such preparations and the surprising fact that by application of the 

 said temperature no butyric-acid but a butylic fermentation ensues, should probably 

 be attributed to the injurious action of the butyl alcohol on the butyric-acid ferments. 



Lr 



Op 



Cultivation of anaerobes by means of Oidium lactis. Gsi large glass dish with the 

 oxygen-absorbing Oidium plate Op. Gsi smaller dish with the culture plate Ka whereon 

 the anaerobic colonies Ak grow. Lr space between the plates. At g the hole in the 

 glass wall of Gst for the escape of the air from Lr, which is afterwards closed with 

 paraffin. Gd glass lid of the large dish Gsi. The higher temperature is at the side of Gd. 



The pure culture is effected as follows. 



Malt-infusion agar with 5 to 10 glucose is liquefied and after cooling to near 

 solidification and addition of a great quantity of Oidium lactis is plated (Op) in a 

 large glass dish (Gsi). At a temperature of 25 to 28 C. the whole surface of the 

 plate is already after 24 hours covered with a thick snow-white film of conidia and 

 the interior of the agar is wholly interwoven with mycelium, which causes a con- 

 siderable absorption of oxygen. 



A second malt-infusion-agar plate (Ka) without Oidium is now prepared in a 

 glass dish (Gs 2 ), much smaller than Gsi. The space between Gsi and Gs? must be 

 large enough Gs? to be caught with the fingers. On its surface a little of the material 

 containing the anaerobes, that is of the crude butyric-acid or butyl-alcoholic fermen- 

 tations, diluted with sterile water, is spread. Now the lid of the smaller dish (Gs-) 

 is removed and the plate pressed on the Oidium plate the agar side (Ka) upward as 

 shown in the figure. 



For the escaping of the air from Lr a little hole g is bored in the glass wall of 



*) Fermentation et ferments butyliques. Archives Neerlandaises I, 39, pag. i. Bacteries 

 actives dans le rouissage du lin. Ibid. Ser. 2. I. 9. p. 418, 1904. 



