72 PRACTICAL BACTERIOLOGY. 



together, from one to ten drops of the resultant liquid 

 are put into one of Bsmarch's tubes, prepared ex- 

 pressly for this purpose. 



The mode of preparation is as follows : test-tubes 

 somewhat larger than usual, and provided with well- 

 fitting india-rubber plugs in which two holes have 

 been bored, are filled in the usual way with gelatine, 

 and sterilised in the ordinary manner. Through the 

 holes in the stoppers two closely-fitting pieces of glass 

 tubing are introduced ; these are bent at right angles 

 over the stopper, one reaching nearly to the bottom of 

 the tube, whilst the other only just clears the stopper; 

 the outer limbs of both are drawn out finely, so as to 

 facilitate their being melted off later. The pieces of 

 tubing, after their free limbs have been stopped up 

 with cotton- wool, are placed for about three hours in 

 the hot-air steriliser, which is kept at a temperature 

 of 160°, whilst the india-rubber stopper is soaked for 

 about an hour in corrosive sublimate solution (1 : 1000). 

 When this sterilisation is completed, the fluid con- 

 taining the bacteria is poured into the liquefied gela- 

 tine in the test-tube, and the cotton-wool stopper is 

 replaced. The operator should carefully disinfect his 

 hands with corrosive sublimate,^ and then quickly 



^ The surest way of disinfecting the hands is to soruh them 

 thoroughly with a brush and spirits of soap, in order to get 

 rid of all fat, etc., and then to wash them well with corrosive 



