426 



T. YOKOI. 



But then the (|ue.stion naturally arises, w hy do the results of 

 those experimenters who took the specific gravity of a seed as the 

 sole standard regardless of its weight all or almost all without 

 exception, agree ? In 1882 I tried to use a solution of common salt, 

 which can be obtained cheap anywhere in our country, as the 

 medium for the selection of rice seeds and got good results. I have 

 named the method the " salt water (or rather salt solution, strictly 

 speaking) selection " method.''^' Thereafter the method has been 

 tried with good results and apjjlied to various seeds, being now 

 widely used especially for rice in our country. The results 1 

 obtained in Chikuzen, where I first tried it may be summed up as 

 follows, the aim of the experiments having been to know tlie com- 

 parative merits of the method in question and the "water selection " 

 method : — 



TABLE IV. 



COMPARATIVE RESULTS OF THE "SALT WATER" 

 AND THE "WATER SELECTION.".';' 



Method of selection. 



I'addy per 

 t.m, koku. 



Wci^jlit of 

 paddy ])er 

 koku, 

 kw an. 



Husked 

 rice per 

 tan, koku. 



Weight of 

 rice per 

 koku, 

 kwan. 



Straw per 

 tan. l^waii. 



Length of 

 straw, 

 shaku. 



' ' Salt water ' ' 



5-571 



26.36 



2.615 



40.S1 



101.165 



3.81 



"Water " 



4099 



25.80 



2.403 



40.02 



99455 



3-74 



Extra i^roduce of 1 

 the former. j 



0.572 



0.56 



0.212 



0.79 



1.71C 



0.07 



According to tliis table, the produce obtained with the " salt 

 water selection " in the form of paddy or unhusked rice was 146.850 

 kwamnie, v. hich when husked gave 100.710 kivauune while with the 

 "water selection" the paddy weighed 128.970 kiuavivic, which 

 when husked gave 96.170 kzcaiiiiiic — thus giving a result in favour of 

 the former. 



Practically the method is carried on in the following manner. 

 A certain weighed quantity of common salt of impure sort is put 

 into a large v.ooden tub with water, and the water is then stirred to 



(5) Wolfifcnstein used already in 1877 specific gravity for the selection of seeds though 

 with a quite different aim. His work was, however, not known to me at that time. See 

 Anleitung zur Getreideziichtung by Dr. K. Rumker, ISerlin 1889. 



(6) Ecsca, Beitrage zur Kenntuiss der Japanischen Lundwirthschaft, Sp. Th. Tokio 1892. 



