Substances in the Wet Way. 



377 



as f follows: A thick walled, round bottom flask of a liter's 

 capacity, serving as an oxidizing 

 chamber, was closed by a rubber 

 stopper with two perforations, 

 through one of which passes the 

 tube of a separating funnel of 

 about 100 cm3 capacity. The tube 

 of this funnel reached nearly to 

 the bottom of the flask and is 

 drawn out at the lower end. A 

 disc of platinum foil is hung in 

 the neck of the flask, nearly clos- 

 ing it, and held in place by a plati- 

 num wire passing through the foil 

 and tucked under the rubber stop- 

 per where the funnel tube enters. 

 The second hole of the stopper is 

 filled by the exit tube, a glass tube 

 of 0*7 cm internal diameter. This tube is expanded just above 

 the stopper to a small bulb which serves to prevent mechanical 

 loss of the solid contents of the flask during the boiling. This 

 tube is joined by means of a rubber connector (provided with 

 a screw pinch cock) to the inlet tube of the absorption flask, 

 which is an ordinary 500 cm3 round bottom flask. This flask is 

 also closed by a rubber stopper with two perforations, through 

 one of which passes the inlet tube described above and through 

 the other the exit tube, which is also enlarged to a small bulb 

 just above the stopper and is closed by a rubber connector and 

 screw pinch cock. The glass ground stopper of the funnel 

 tube is carefully cleaned and lubricated with a thick solution 

 of metaphosphoric acid. 



Instead of getting the vacuum by the water pump, it may 

 be gotten almost as quickly and certainly more simply by boil- 

 ing water in the evolution flask and the barium hydroxide 

 solution in the absorption flask at the same time — both flasks 

 being connected ready for making a determination. When 

 steam issues in good quantity from the exit tube of the absorp 

 tion flask, the 

 flask and its 



under the absorption flask and its screw pinch cock also quickly 

 closed. The flasks are then allowed to cool. 



In making a determination, the organic substance is weighed 

 out in a counterbalanced bulb, so thin that it may be easily 

 broken later and made with a wide mouth for convenience in 

 introducing the solid substance. After the substance is 

 weighed, the mouth of the bulb is sealed by heating in a 

 small blow-pipe flame and the tube introduced into the evolu- 



burner is removed from under the evolution 

 screw pinch cock closed, and then the burner 



