408 



AGRICULTURAL ANALYSIS 



A is a round flask of about 150 cubic centimeters capacity, 

 furnished with a well-fitting rubber stopper provided with two 

 holes, one for the entrance of the funnel tube B and the other 

 for the delivery tube C. The tube B ends about two centimeters 

 above the bottom of A and carries a bulb-shaped funnel at its top 

 capable of holding about 50 cubic centimeters. The gas tube 

 D is ground into the bulb of B as shown in the figure. 



After the flask has been filled with the solution to be ex- 



Fig. 24. Spiegel's Apparatus for Nitric Acid. 



amined, carbon dioxid is conducted through D and the flask 

 is heated to boiling until the gas which escapes through C no 

 longer contains any air. The measuring tube is brought over 

 the end of the delivery tube C, in the usual manner; but is not 

 shown in the figure. In the funnel of B are placed 20 cubic 

 centimeters of previously prepared and boiled ferrous chlorid 

 solution and this liquid is allowed to flow partly into A by lift- 



