Cultivation 541 



mating a potato in composition, but without dextrin or glu- 

 cose. The composition is as follows: 



Distilled water 1000.0 grams 



Asparagin 6.0 " 



Oxalic acid 0.5 gram 



Lactic acid 0.15 



Citric acid 0. 15 



Disodic phosphate 5.0 grams 



Magnesium sulphate 2.5 



Potassium sulphate 1 .25 



Sodium chlorid 2.0 



All the salts excepting the magnesium sulphate are 

 powdered in a mortar and introduced into a flask with the 

 distilled water. Thirty grams of Witte's or Grubler's pep- 

 tone are then added and the mixture heated in the auto- 

 clave under pressure for one-quarter hour. As soon as 

 removed, the contents are poured into another flask into 

 which 120-150 grams of gelatin had previously been placed. 

 The flask is shaken to dissolve the gelatin, and the contents 

 then made slightly alkaline with soda solution. The mix- 

 ture is again heated in the autoclave at 110 C. for one- 

 quarter hour, then acidified with a one-half normal solution 

 of sulphuric acid, so that 10 c.c. have an acidity neutralized 

 by 0.2 c.c. of one-half normal soda solution. This acidity 

 is equal to 0.5 c.c. sulphuric acid per liter. After shaking, 

 place the flask in a steam sterilizer for ten minutes, then 

 filter. When filtered, verify the acidity of the medium, 

 correcting if necessary. Finally, add the magnesium sul- 

 phate, dissolve, dispense in tubes, and sterilize by the inter- 

 mittent method. 



At the moment of using, put into each tube i c.c. of a 

 35 per cent, solution of lactose and o.i c.c. of a 2.5 per cent, 

 solution of carbolic acid. 



Upon this medium, the colonies of the typhoid and colon 

 bacilli show marked differences. The colon colonies are 

 yellowish-brown, the typhoid colonies bluish-white and 

 small. Fine bubbles of gas from the fermentation of the 

 lactose often occur about the colon colonies. 



By this method Remy was able to isolate the typhoid 

 bacillus from the stools in 23 cases which he studied. He 

 believes that the constant presence of the typhoid bacillus 

 in the stools of typhoid fever, and its absence from them 

 under all other conditions, is a far more important and 



