'•THAT BAD BEVERAGE, BEER" 375 



provision for the expansion of the contents of the seed, such 

 as takes place when it is moistened. This expansion would 

 burst the seed-coverings; and the fact that the shape of the 

 seed prevents any rupture suggests that the coverings are 

 to be maintained entire for some such purpose as can be 

 carried out by means of their semi-permeable property. 



But even this unique and hitherto unsuspected feature of 

 the seed-coverings is less remarkable than the one which 

 came to light in the course of further investigations, and 

 which revealed the power of selective permeability in the 

 presence of certain solutes. Thus, if the seed of barley is 

 immersed in a mixture of solutions of mercuric chloride and 

 sulphuric acid, the former salt passes through the seed-cover- 

 ings with apparent ease and itself diffuses into the seed, while 

 the sulphuric acid is kept outside. In a similar fashion acetic 

 acid and the fatty acids generally are able to pass through 

 the seed-coverings ; but the salts of these acids, such as sodium 

 acetate, are excluded. More remarkable still is the fact that, 

 whereas acetic acid enters and diffuses through the seed very 

 readily, the corresponding amino-acid, glycine, will not enter 

 at all. Aqueous solutions of ethyl alcohol, aldehyde, acetone, 

 and ethylic acetate diffuse into the seeds very readily ; but in 

 the anhydrous state these liquids are excluded. The only 

 explanation of this property of selective-permeability which 

 can be suggested at present is that it is related in some way 

 to the mode in which the molecules of the various solutes are 

 united with the molecules of solvent water. Such an explana- 

 tion appears to support the views on solution which have 

 been advanced by Prof. H. E. Armstrong. 



The investigations just described have not yet been brought 

 to the final stage, but enough has been done to furnish yet 

 another illustration of the value of the brewing industry as an 

 incentive to scientific research. Of its importance in the world 

 of commerce and its antiquity as a craft, business men and 

 historians can supply evidence. It has remained to certain 

 classes of politicians and ill-balanced enthusiasts to hamper 

 the provision of a pure and wholesome drink and to surround 

 " that Bad Beverage, Beer " with an odium which is as harmful 

 as it is undeserved. 



