fi Wiiitrr W/ic(if \'<trli(ics (uid W'liifci-A'i/liiii/ 



fitted two reflux coudensers and a bent glass tube leading to the distillinji 

 flask below. The siphon also passed through the stopper of the distilling 

 flask. The samples were transferred to one of these extractors and ex- 

 tracted with 8U per cent, alcohol on a steam bath for 30 hours, by which 

 time the Molisch a-napthol test on the alcohol in the extractor always 

 became entirely negative. In transferring material from one container 

 to another, the emptied container was thoroughly rinsed with hot 

 alcoiiol. 



The extract was concentrated in the apparatus illustrated by Van 

 Siyk(>(ifi. Fitr. I) under a pressure of less than 30 mm., with the dis- 

 tilling flask in a water bath at a temperature of Uf to 50° C. When 

 reduced to a volume of 7') to ItXlt-.c. about 200 c.c. of distilled water 

 was added and the solution reconcent rated to get rid of the last traces of 

 alcohol. This precaution was found necessary since the presence of 

 alcohol affected the subsequent determination of amino nitrogen. The 

 recoucent rated extract was then transferred to a 'jrjO cc. volumetric 

 flask by Altering through a pad of cheesecloth in a small funnel, making 

 it nearly to volume by several successive washings of the distilling flask 

 with small portions of boilingwater. Apad of cheesecloth four layers thick 

 was found the most satisfactory filter for removing the solid particles 

 of chlorophyll which separated out. All otlier materials tried clogged 

 at once. The extract was then cooled to room temperature and made up 

 to volume. 



All volumetric flasks and jjipettes used throughout the analyses were 

 standardised in true cubic centimetres at 20° C. 



Amino Nitnuferi. The amino nitrogen was determined by the usual 

 Van Slyke apparatus, using 10 c.c. portions of the extract, filtered for 

 removal of fine particles which had escaped the cheesecloth filter. Since 

 preliminary trials had given a somewhat higher yield when deamination 

 was continued for 30 minutes instead of the usual live minutes, the former 

 period was adopted. Of this time, shaking was done during the first 

 mintite and the last two minutes. 



Water-Solubh Nitrogen. The total water-soluble nitrogen in the 

 alcoholic extract was determined by the Kjeldahl-(4unning-Arnold 

 method, using 10 c.c. portions of the concentrated extract, filtered as 

 for amino nitrogen. 



Oleariny Extract for Sugar Analysis. After the portions required for 

 nitrogen determinations had been removed, the remainder of the extract 

 was cleared with dry powdered lead acetate. The dry defecation method, 

 first proposed by Horne(a), has tlie advantage not only of largely 



