TRANSACTIONS OF SECTION B, 665 



of the quantities of the acting parts changes in one or the other direction. The 

 velocity of reaction, hefore imperfect equilibrium takes place, i'ormecl the subject 

 of investigation of many scientists ; Vernon-Harcourt and Esson, van 't Hoff, Guld- 

 berg, and Wange, should be specially mentioned. The author huds in the case of 



solidification acd crystallisation that the equation r^ = c (^^ — f), or =c'{f.^ — t)\'s, 



nz dz 



to be applied, but would express the common equation as ,' =/(^o~0i since the 



velocity of the reaction can often be complicated by other phenomena. 



Let us now bring into connection the equations for the two kinds of velocity of 

 reactions with the two kinds of equilibrium. 



lu the case of imperfect equilibrium we have, before the state of equilibrium is 

 arrived at, two reactions: 



dv 



~ = c{A — .v) (B — a') (alcohol + acid) 



ds 



fd.i 



(j^y = c'.v'~ (ether + water), 



and equilibrium is arrived at when c(A — .r') (B — .r') = e'.r'^, ?'.e., both reactions 

 take place simultaneously and the equilibrium is a dy7iamic one. In the case of 

 perfect equilibrium we have before the equilibrium is arrived at 



and equilibrium is arrived at when <y — < = {i.e., at the freezing temperature); 

 — therefore at the point of equilibrium equals 0, that is to say, no further reaction 

 takes place, and the equilibrium is a static one. 



9. Chemical History of Barley Plants. By C. F. Cross and C. Smith. 



Work has been carried out over a period of two years (1894 and 1895) upon 

 crops grown on the experimental plots at AVoburn. Maximum plot 6 and minimum 

 plot 1 were investigated with regard to the fiu'fural and permanent tissue which 

 they contain. 



A table of results is appended to the paper. 



From the table we draw the following conclusions : — 



1. The conditions of soil nutrition have very little influence upon the composi- 

 tion of the plant. 



2. The feeding talue of straws grown in wet seasons is high, and conversely 

 the paper-making value of such straws is low. 



'6. The furfuroids are continuously assimilated to permanent tissue in a normal 

 season, but in a dry season, on the other hand, the permanent tissue is pat under 

 contribution for nutrient material, which is ordinarily drawn from the cell contents. 



