March 2, 1906.] 



SCIENCE. 



327 



are pointed out and exact conditions for 

 its use prescribed. 



The results obtained on uniform samples 

 by twelve collaborating chemists using 

 miscellaneous methods and also using the 

 method suggested by the writers, are given. 

 It is demonstrated that with proper pre- 

 cautions results can be obtained which are 

 reasonably accurate. 



The Estimation of Hydrocyanic Acid in 

 Cassava: C. C. Mooke. (By title.) 



The Artificial Coloring Matter in Whiskey: 

 P. H. Walker and J. H. A. Schreiber. 

 A series of tests for artificial coloring 

 matter in M^hiskey were described and a 

 summary of results on a very large number 

 of whiskies, both pure and artificially col- 

 ored, discussed. 



A Uniform Method for the Determination 

 of Reducing Sugars: P. H. Walker. 

 The same solutions and manipulations 

 are used in the determination of both dex- 

 trose and invert sugar. The alkaline tar- 

 trate solution is the same as Soxhlet's; but 

 the copper solution contains 40 grams of 

 crystallized copper sulphate to 500 c.c. 

 Adhering to the directions given, the values 

 for varying amounts of dextrose and invert 

 sugar were determined and a table pre- 

 pared showing the weight of cuprous oxide, 

 dextrose and invert sugar corresponding to 

 each milligram of copper from 10 to 466. 



The Extraction of Tanning Materials for 

 Analysis: F. P. Veitch and H. H. Hurt. 

 (By title.) 



The Ripening of Oranges: W. D. Bigblov/ 



and H. C. Gore. 



This work is in connection with the sys- 

 tematic study being made by the writers, 

 of changes that occur in fruit during its 

 growth and ripening. The oranges in- 

 creased in actual weight of total solids and 

 sugars from the beginning to the full 

 maturity of the fruit. At all stages of 



the growth of the fruit, the total sugars are 

 divided about equally between reducing 

 sugar and sucrose. The marc of the 

 orange is formed very early in its history 

 and remains constant in weight during its 

 growth and development. The acids are 

 also formed at an early stage and appar- 

 ently increase gradually but almost im- 

 perceptibly. 



Storage of the fruit at all stages of its 

 development results in slight loss of total 

 sugar, a marked increase of reducing sugar, 

 and a corresponding loss of sucrose. The 

 loss of total sugar noted above is to be ex- 

 plained as in the case of apples, by the 

 consmnption of reducing sugar as a result 

 of the respiration of the fruit. The weight 

 of marc remains practically constant and 

 the weight of aeid appears to decrease 

 slightly on storage during the various 

 stages of the development of the orange. 



The Growth and Ripening of Persimmons : 



W. D. BiGELOw, H. C. Gore and B. J. 



Howard. 



This paper is a partial report on the 

 systematic study of the ripening of fruits 

 which is being conducted by the writers. 

 In the other fruits thus far studied, the 

 quantity of tannin was so low as to pre- 

 clude any deductions from the results ob- 

 tained at various stages of their growth. 

 The persimmon was selected largely be- 

 cause of its content of a relatively large 

 amount of tannin. 



The weight of the pulp increases steadily 

 during the entire period of observation and 

 a marked increase was also noted in the 

 ease of total determined solids, sugar and 

 mare. The sugar was found to consist 

 almost entirely of invert sugar. The 

 amount of sucrose is apparently almost 

 within the limit of analytical error. The 

 percentage of acids is also very low. Dur- 

 ing a later portion of the period of observa- 

 tion, the tannin was found to decrease in 



