555 



Studies on the ripening of cherries, on the products of fermen- 

 tation of cherry and currant juices, and on the coloring matter 

 of black and of red currants, W. Keim {Zeitsch.f. analyt. Chem., 13, 

 pp. 401—137). — In his studies of the changes during the growth and 

 ripening of the fruit of the cherry {Prunus cerasus — early egriot), the 

 author paid especial attention to the nature of the acids and the sugars 

 present, since he projiosed to study the products of fermentation of the 

 juice. Between May 15 and June 19 samples of the fruit were gathered 

 at intervals of from 1 to 2 weeks, and submitted to chemical and micro- 

 scopical tests. The results of these follow : 



Cherries at different stages of ripening. 



Date. 



May 15 

 May 21 



May 28 

 June 10 



June 19 



Acids 

 present. 



Malic, citric, 

 and s u c- 

 cinic. 



....Do 



...Do 



Malic and 



citric. 

 .--.Do 



Glucoses yjrea- 

 ent. 



Not deter- 

 mined. 



Dextrose, Icvn- 

 lose, and ino- 

 site. 

 Do. 



!N o t deter- 

 mined. 



Dextrose, levu- 

 1 o 8 e, and 

 traces of 

 inosite. 



The cane sugar in the leaves was determined on the four last dates, 

 the percentages found being 0.436, 0.465, 1.321, and 0.831 respectively. 



With the commencement of the development of the fruit the dry matter 

 increased steadily from 11.12 to 17.87 per cent. At the time the latter 

 content was reached an increase in the size of the fruit took place, the 

 average weight of ten cherries increasing from 13.2 to 30.8 grams. With 

 this increase in weight the percentage of sugar in the fruit doubled and 

 increased in the leavesj and the starch disappeared from the fruit and 

 increased in the fruit stalk. The increased weight of the fruit is 

 believed to have been due to an additional storage of water and accel- 

 erated sugar production during this period. The percentage of acids 

 increased throughout the ripening, which is contrary to the old view that 

 the sugar is formed at the expense of the acids. The sugar in the leaves 

 increased with the increase of sugar in the fruit, and diminished when 

 the fruit became ripe, which is in accord with observations by Keubauer 

 and Hilger on the grape. No other sugar but cane sugar was detected 

 in the leaves (the probable seat of its formation) and since no acid was 

 present in the leaves, thus excluding the possibility of an inversion, 

 the author is led to assume that cane sugar is the first stage in the 

 production of the sugar, the glucose in the fruit resultiug from an 

 inversion by means of the acids there. 



