Fungus of Lolium. 287' 



The essential part is the condeiisiiit; tubes A B, which is of pure 

 tin. Before the entering steam can reach the condenser, it must 

 travel round two copper-sheet batHes C and D, which effectively 

 retain liquid particles projected from the boiler. The condensate 

 drips into the tin-funnel E, and is collected in a 3-litre Jena glass 

 flask, wit-h the usual guard tubes of soda lime. It is removed from 

 the flask by siphoning. The outer cylinder is of copper, and is 

 protected by asbestos sheeting on the outside. No water whit-h 

 condenses on the cylinder or the copper batfles-plates can enter 

 the funnel E; it is drained away at F. To prevent tlie coaidensate 

 running down A B from the soldered junction of the tube 

 with the top of the cylinder, a tin flap is welded on, as shown at 

 G. The drippings from this fall outside the funnel E. The 

 middle fraction of 3 litres is the purest. 



Apparatus. 



Two large glass shades, fitted into a groove round the peri- 

 phery of wooden stands, were used for covering the pots, in 

 which the grains were planted. Ihese were carefully cleaned with 

 acid-dichromate cleaning mixture. In each case a long glass tul^e 

 bent at right angles to itself was inserted through tlie stand into the 

 cylinder. These were connected in turn to a series of wash-bottles. 

 The first of these contained chemically pure sulphuric acid, giving 

 no nitrogen reactions. This acid bottle was connected to two series 

 of water-wash bottles, one set belonging to each cylinder. The con- 

 nections were made with glass and rubljer tubing. Between the last 

 wash-bottle and each shade, a tube of wider diameter, was inserted, 

 containing a germ-proof cotton plug. A second tube of smaller 

 length, also bent at right angles and fitted through the wooden 

 base into the other side of the cylinder functioned as an exit tube. 

 These in turn were connected each to a wash-bottle, and then to a 

 water pump. By this means a slow current of air could be kept 

 drawn through the cylinders. Before reaching them, the air had 

 to pass through the acid, two wash-bottles containing nitrogen- 

 free water, and finally through the cotton plug, so all combined 

 nitrogen in the form of dust, etc., was removed before the air 

 reached the pots. This treatment also reduced to a minimum the 

 chance of nitrogen fixing bacteria, present in the atmosphere, 

 gaining access to the sand. 



After the experiment had been running for some little time, it 

 was evident that a larije amount of water was being carried over- 



