98 Messrs Wood and Berry, A rapid method of estimating sugar. 



reducing action of an amount of cuprous oxide containing 

 "01 gm. metallic copper. The actual strength is just over 5 gms. 

 of potassium permanganate per litre ; it is standardised by 

 weighing the copper obtained by reducing the cuprous oxide from 

 10 c.c. of *5 per cent, glucose solution, and titrating duplicates. 

 The method is rapid, accurate, and very easy to carry out, and 

 enabled the authors to determine the sugars in about 150 samples 

 of swedes in a very short time. The use of permanganate in 

 this way was suggested in the Annual Report of the U.S. Dept. 

 of Agr. 1879, but has not been used to any extent on account of 

 the trouble of dissolving the cuprous oxide in the ferric sulphate. 

 This is entirely overcome by proceeding as above, and the method 

 should now be a very convenient one. 



Selection of seed by chemical methods. By T. B. Wood, M.A., 

 Reader in Agriculture, and R. A. Berry. 



[Read 2 March 1903.] 



The selection of plants for seed-bearing is a subject which has 

 received abundant attention, but except in a few important cases 

 the chemical composition of the mother plants has been almost 

 entirely neglected. Selectors have succeeded in a marked degree 

 in improving such external characters as shape, size, colour, and 

 cropping power, as is evidenced by the excellence of these 

 characters in the common varieties of agricultural plants, but 

 chemical selection has been used only in such cases as sugar-beet 

 and wheat. The chemical selection of sugar-beet is carried out 

 by determining the sugar in a very large number of individual 

 roots, and growing seed only from those containing an exception- 

 ally high percentage of sugar together with a low percentage of 

 objectionable impurities. Such work has been carried out by 

 many continental seedsmen, and by many of the leading sugar 

 manufacturers, and has resulted in more than doubling the sugar 

 content of the beet in about 50 years. 



Improved varieties of wheat have also been brought out by 

 Hays {Univ. of Minnesota, JExpt. Stn. Bulletin 62, 1899) as the 

 result of selecting seeds from among the produce of plants bearing 

 seed which was found to produce flour of good colour and con- 

 taining a high percentage of gluten of good qualit} 7 . 



Hays' system of working was in the first place the selection of 

 varieties which suited his district as shown by their yielding well 



