Research Lahoratory of the Uoynl Collff/f of Physidans. r!o7 



test tubes with a pipette, the following method (Fig. 17) has 

 been devised, — into each of the large stock flasks, in which 

 the peptonised gelatine is sterilised and stored, is fitted an 

 india-rubber bung with two openings. Through these pass 

 two tubes, one with a tliistle head tube running to near the 



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surface of the gelatine, i.e, about two-thirds of the distance 

 down into the flask, the other passing just through the cork. 

 To the shorter tube is fitted a piece of india-rubber tubing 

 on which is a Mohr's clip, and to the other end of this 

 tubing is fitted a piece of glass tubing with a constricted 

 orifice. A plug of carefully sterilised cotton wadding is 

 pushed into the thistle head, the india-rubber bung is pushed 

 into the neck of the flask, and then a sheet of cotton wadding 

 is placed over the whole of the tubes and the mouth of the 

 flask, and is held in position by an india-rubber band. The 

 flask is placed in the steam steriliser, where it may be left 

 for a sufficient length of time to allow of it becoming perfectly 

 sterilised. It is filled nearly a third full with gelatine, after 

 carefully removing the sheet of wadding and the bung ; these 

 are then replaced, and the whole is again sterilised as usual. 



When the gelatine is to be drawn off into test tubes, the 

 flask is inverted and held in a retort stand, the sheet of 

 wadding is carefully removed and folded, the glass nozzle is 

 inserted into the mouth of the test tube, the clip is opened 

 and gelatine escapes ; all the air passing into the flask, being 

 filtered through the wadding in the thistle head funnel, is 

 thoroughly sterilised. If the whole of the gelatine is not 

 withdrawn, all that is necessary ^s to replace the sheet of 



