46 ANNALS OF THE MISSOURI BOTANICAL GARDEN 



[Vol. 6 



The apparatus is shown in pi. 2, which is practically self- 

 explanatory. All parts except the condenser jacket G are 

 made from Pyrex glass, which may be worked with an oxy- 

 illuminating gas flame. The bulb A is conveniently made 

 from a 200-cc. flask, the neck being drawn down and sealed 

 to the condenser tube F. The tip of the curved tube in 

 bulb A is perforated by several holes at its lower point. 



Tube C is attached to the 500-cc. Kjeldahl flask E by a ground 

 joint at D. 



One objection to the apparatus in this form is its rigidity, 

 which, on shaking to mix the alkali, in the Kjeldahl pro- 

 cedure, renders the likelihood of breakage high. To over- 

 come this we have used a rubber joint at B, which does not 

 appear to vitiate the results if the glass tubes are fitted 

 closely end to end. An extreme case was taken to test this 

 fault and the general efficiency of the apparatus. Solutions 

 of N/100 acid and alkali were prepared and carefully stan- 

 dardized. A dilute solution of ammonium hydroxide was care- 

 fully titrated against the solutions, using methyl red as the 

 indicator. Successive equal portions of this ammonium hy- 

 droxide solution were distilled in the apparatus and the dis- 

 tillate titrated with the above-described solutions. Among 

 the following data those results indicated by an asterisk were 

 obtained in an apparatus with a close rubber joint at K. 



N found 

 (mgs.) 



0.101 

 0.105 

 0.103 

 0.101 

 0.098 



0.103 



0.099 

 0.098 

 0.105 

 0.105 



Nitrogen taken 0.103 mgs 



Error 

 (mgs.) 



-0.002 

 0.002 

 0.000* 



-0.002 

 -0.005* 

 0.000 

 0.004 

 -0.005* 

 0.002 

 0.002* 



Average 0.102 Average deviation 0.0024 



Scrubbing bulb A effectively removes the alkali entrained 

 in the vapor when distillations are made over strongly alka- 



