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the neck of the washing-bottle to a measuring-flask of 100 c. c. capacity, and this 

 process was performed 3 times. Finally the measuring flask was filled to the 

 index-mark and closed with a cork, shaken well and put aside, until the barium 

 carbonate had been precipitated. Of the clear solution 20 c. c. was drawn off with 

 a pipette and titrated against standard hydcocloric acid using Phenolphthalein as 



an indicator. When the strength of the KHO solution in all three washing-bottles 

 had been measured in this way, the quantity of the carbon dioxide produced could 

 be estimated. The strength of the KHO solution in the third washing-bottle was 

 not reduced by the current of air and proved thus the absorption of the CO., to 

 be complete. To eliminate any error arising from the circumstance of KHO- and 

 ßaC/o-solutions containing small amounts of CO., a control titration was always 

 made with these solutions. The whole quantity of CO., , produced during the ger- 

 mination until the moment, when the plants were prepared for quantitative ana- 

 lysis, being thus estimated, it was possible to calculate the quantity of carbohy- 

 drates decomposed by the respiratory process during the germination (cfr. p. 24). 

 The plants were prepared for chemical analyses in the following manner. The 

 plants were crushed in a mortar as completely as possible and transferred to an 

 Erlenmeyer flask together with 70 per cent alcohol; if analyses of sugars were to 

 be performed some Ba CO3 was added to neutralize any acids contained in the plants. 

 As a rule the amount of alcohol used was 10 times as large as the amount of the 

 dry-weight of the plants. After this process the portions were boiled on the water- 

 bath in order to destroy the enzymes. After a few days the portions were boiled 

 again and alcohol was added until the previous weight was regained. After this 

 process the material used for the experiments was put aside for at least one week 

 before it was analyzed. One week has proved by experiments to be sufficient for 

 the extraction of the various components. 



The analyses were carried out in the following way: A certain quantity of 

 the alcoholic extract was filtered and almost evaporated to dryness on the water- 

 bath; the residue was dissolved in hot water and transferred to a measuring-flask, 

 and a suitable quantity of 10 per cent tannic acid and a few drops of lead acetate 

 were added; by this process proteids and partially albumoses were precipitated, 

 while peptones and amides remained dissolved [Sebelien p. 135]. It must be noted 

 that I have always used equal quantities of précipitants for the separate portions 

 belonging to the same series. The précipitants were not added till the liquid had 

 cooled down to the temperature of the room, as the precipitation remains uncom- 

 plete, if undertaken at a high temperature. [Weis p. 29]. After this the measuring- 

 flask was filled with water to the mark and put aside for at least 20 hours before 

 the liquid was filtered, and a certain amount of the filtrate was used for estimation 

 of nitrogen by Kjeldalil's method. In some of the experiments part of the filtrate 

 was precipitated by phosphotungstic-acid of a strength of 25 p. c, concentrated sul- 

 phuric acid being previously added in such portion that 10 p. c. of the whole 



