456 ABSTRACTS 



Associated with pyorrhea alveolaris, various types of bacteria have 

 been recognized for some years, and recently certain protozoa. A re- 

 view of the more important contributions on the bacteriology and 

 protozoology of these cases is given. Under treatment the use of 

 ipecac and emetine as an amebicide against Entameba buccalis is dis- 

 cussed, likewise the use of ammonium bifluoride, as recommended 

 by Head, as a bactericide. The use of bacterial vaccines (bacterins) 

 is indicated, especially when the condition does not respond to local 

 treatment, or when it becomes systemic. The technique of collecting 

 the material for, and the . preparation of, bacterial vaccines is out- 

 hned. In considering the use of autogenous and stock vaccines the 

 author holds that in certain cases a polyvalent stock vaccine is suffi- 

 cient. A discussion of the theoretical principles of immunity in rela- 

 tion to vaccine therapy is presented. — L. W. F. 



BACTERIOLOGY OF SOILS 



Variation in Nodule Formation. L. T. Leonard. Jour. Amer. Soc. 



Agronomy, 1916, 8, 116. 



Varying degrees of susceptibility between varieties of the soy beans 

 to inoculation regarding the production of nodules were investigated. 

 Nineteen varieties of soy beans were taken and inoculated with 1 cc. 

 of a broth culture of the soy bean organism. From the results obtained, 

 the author draws the conclusion that a soy bean culture isolated from 

 a single strain of soy beans will be successful in inoculating any of 

 the varieties studied. — A. I. 



Nitro-cultures and their Commercial Application. F. C. Harrison. 



Trans. Roy. Socy. Can., 1915, Ser. Ill, 9, Sec. IV, 219-223. 



The writer refers to the paper presented to the Royal Society in 

 1906 by himself and Barlow on "The Nodule Organism of Leguminosae — 

 its Isolation, Cultivation, Identification and Commercial Application." 

 He reviews the commercial application of the methods then described, 

 and notes that several firms in the United States have manufactured 

 and distributed nitro-cultures according to these methods. The On- 

 tario Agricultural College and the Macdonald College, Quebec, have 

 sent out some 32,000 cultures with very favorable results, particularly 

 with Alfalfa and Red Clover. Further experiments with media are 

 reported, and the following revised medium which has been used suc- 

 cessfully for the past two years is recommended. 



Three solutions are prepared: 



A. 75 grams of agar are dissolved in 3000 cc. of water, by placing 

 in the autoclave at 10-15 pounds pressure. 



B. 25 grams of hard wood ashes are boiled in 1000 cc. of water and 

 filtered. 



C. 0.5 gram of acid potassium phosphate, 0.5 gram of magnesium 

 sulphate, 0.5 gram sodium chloride, 0.25 gram calcium sulphate, 6.25 



