( 83 ) 



therefore, a diastatic ferment had diffused from the fruits and from 

 the juice, which had transformed all the starch, ii could get hold 

 of through the state of dextrin into sugar. 



When the iodine solution was allowed to act too long on the 

 jelly, the iodine penetrated through thé surface layer and reached 

 the lower one, where the starch was still unattacked, thus colouring 

 the whole dish blue. Finally pieces of banana and tamarind fruit 

 were placed on slices of sterilised potato ; the result was that the sacchari- 

 tication of the starch caused more or less deep cavities to appear in 

 the places where the fruits had been applied. 



All this however is not yet a direct proof that the saccharitication 

 has been occasioned by a ferment; and in order to make this clear 

 I immersed slices of banana into alcohol, left them there during a 

 couple of days, then took them out, expelled the alcohol by means 

 of a current of sterilised air and placed them again in Petri dishes 

 on a layer of starch emulsion stiffened with isinglass and agar agar. 

 Though not so rapid as in the case of the much more juicy fresh 

 fruit, yet also here the ferment diffused through and after the application 

 of the iodine solution the white stains with the red borders became 

 visible. 



A quantity of mango juice was added to a boiled and re-cooled 

 solution of 3% starch at 50° C. and kept at that temperature for 

 some time. The liquid, which, at the outset, had given a deep blue 

 reaction with iodine solution only became red when at the end of 

 the experiment this test was repeated ; this coloration did not undergo 

 any change even if the mixture was kept for some time longer or 

 if a fresh quantity of mango juice was added. The total amount of 

 sugar, contained in the liquid (for the mango juice itself had also 

 contained sugar) was higher after the reaction than before, which 

 showed that the mango juice had contained a diastatic body with 

 power to transform starch into dextrin and into sugar. 



Now the question still remained which sugar is formed in the 

 laboratory outside of the living organism. 



The ripening fruits and their juices already contain so much sugar, 

 which mixes with the small amount of sugar formed by the sacchari- 

 tication of the starch that the proper identification of that latter 

 portion is extremely difficult if not impossible. 



In order to eliminate the influence of the already existing sugar, 

 ripening banana fruits were peeled and repeatedly triturated with 

 alcohol and the extracted pulp, which contained as little sugar as 

 possible was pressed and brought into glycerin. After a few days the 

 amount of sugar and its nature was ascertained in the glycerin by 



6* 



