and Laboratory Methods. 1825 



CURRENT BACTERIOLOGICAL LITERATURE. 



H. W. CONN, Wesleyan University. 



Separates of Papers and Books on Bacteriology should be Sent for Review to H. W. Conn, 

 Wesleyan University, Middletown, Conn. 



Pakes. On the Value of Plating as a Means ^he author has attempted to test the 

 of Determining the Number of Bacteria in value of the ordinary methods of 

 Drinking Water. Cent. f. Bac. II, 7: 386. , . . , . . 



Studying water in determining the 



actual number of bacteria, and reaches some rather unexpected conclusions. He 

 finds, in the first place, that the ordinary nutrient gelatin is not a favorable 

 medium for bacteria growth. He finds, indeed, that a medium made by dis- 

 solving gelatin in distilled water and then neutralizing with NaOH without the 

 addition of meat extract or gelatin is the medium in which the water bacteria 

 apparently grow the best, for such gelatin give larger numbers than the ordinary 

 nutrient gelatin. He then tests nutrient material made of gelatin dissolved in 

 waters and finds wide differences in the number of bacteria which grow in the 

 different samples of gelatin dissolved in water from different sources. The great 

 irregularity leads him to believe that in order that the largest number of bacteria 

 possible should be obtained the culture media should be as nearly as possible 

 like that of the water tested. He concludes in general that the use of ordinary 

 gelatin gives no necessary criterion of the number of bacteria present in water. 

 Sometimes, indeed, the results are widely out of harmony with the actual num- 

 bers. He recommends that the gelatin culture medium to be used should be 

 made without meat extractives and should be made with the water which is to 

 be examined, and claims that the best nutrient material is that of pure water 

 with gelatin and without any further additions, except for neutralization. 



H. W. C. 



Turro. Zur Anarobenkultur. Cent. f. Bac. I, A simple, practical device for the iso- 

 ■ '^^' lation of anaerobic bacteria has been 



described by the author, and consists of the following : 

 The apparatus used is shown in the 



accompanying figure. It consists of a 



common Petri dish with glass rests fast- 

 ened upon the inner side, and a glass 



disk which just fits into the Petri dish, 



resting vrpon the glass supports. For 



use the gelatin culture medium is heated 



in an autoclav to drive out all the air. It 



is then poured upon the glass disk and 



inoculated. After it has hardened there 



is placed in the dish a quantity of pyro- 



gaUic acid and NaOH, and then the disk, with its inoculated gelatin, is placed 



upon the rests, with the gelatin side down. Melted paraffin is poured around 



