BY B. GRBKi-SMITH. 



75 



Calt'ium iiitrati'. a(| 2()() 



'Jalcium i-hlorkle 175 



Caleium lactate 152 



Magnesium sulphate. a(| 132 



Potassium mondliydiotjeii ])hospliate . . . . 105 



Sodium acetate 88 



No salt 85 



Sodium succinate 82 



Sodium lactate 80 



Potassium-sodium tartrate, acj 57 



The influence of the salts of the earths in promoting- the formation of the 

 ropy substance is clearly shown. Potassium, as represented by the phosphate, has 

 more influence than the indifferent salts of sodium. The weights of slime 

 obtained from the media containing the lactates of caleium and sodium show that 

 the base and not the acid is the active component of the salt, but that the acid 

 has some influence is indicated by the slime obtained in the presence of sodium- 

 potassium tartrate. 



These results were obtained in a medium containing glycerin, which in other 

 tests had been found to maintain the original reaction or to bring about an alka- 

 line condition of the medium. Dextrose and other sugars produced an acid eoti- 

 dition and as wattle bark extracts are acid and as the carbohydrate in such ex- 

 tracts is probably of the nature of dextrose, possibly as a glucoside, it was con- 

 sidered advisable to test the activity of the bacteria in media containing this sugar 

 with various salts. Accordingly a fluid containing dextrose 1 %, meat-extract 

 0.25 %, was prepared, .and portions of it received 0.1 % of anhydrous salt. 

 After sterilisation the sets were infected with bacteria which had been (aken from 

 pure colonies upon the previous day. 



Table xvi. — Salts with Dextrose 1%. 



