Jan. 1896.] BOTANICAL SOCIETY OF EDINBURGH. 493 



ture, has a stimulating action during germination, as well 

 as at other periods of growth, is a well-known fact. The 

 problem for brewers and others using malted grain to 

 solve, is the amount of moisture required to produce the 

 necessary changes at the usual temperature of growth, in 

 order that the resulting malt may have those properties 

 most suited to their wants. The determination of this 

 degree of moisture is of considerable importance, since 

 an inadequate supply prevents a sutticient metabolism of the 

 constituents of the endosperm ; while with a too abundant 

 quantity the internal changes are carried too far, and 

 besides the waste of starch and other desirable substances, 

 there are apt to be formed certain nitrogenous compounds 

 of a soluble nature, which, though of service when in 

 moderate quantity, become a source of trouble if they are 

 unduly predominant. Practice has of course determined 

 for different brewers the amount of moisture to be em- 

 ployed by them in producing a malt most suited to their 

 requirements, still many of them work rather in the dark 

 in this respect, and I thought an inquiry into the subject 

 might be of some ser\ice in bringing to light a few points 

 in connection with the influence of moisture on germina- 

 ting barley. 



With this object in view I have carried out a series of 

 experiments on different barleys, with varying degrees of 

 moisture, to determine the following points : — 



1. The Quantity of Carbonic Anhydride exhaled. 



2. The Dry Weight of the Embryo at the end of the 



Germinative Period. 

 8. The Eatio of the Weight of Carbonic Anhydride 

 exhaled to the Increase in the Dry Weight of the 

 Embryo. 



4. The Amount of Moisture in the Endosperm and in 



the Embryo at the end of the Germinative Period. 



5. The Activity of Growth as shown by the Daily 



Amount of Carbonic Anhydride exhaled. This 



point being made plain by the construction of 



curves. 



I do not propose, in this paper, to touch the problem 



connected with the compounds produced by metabolism 



under varying conditions of moisture. I have done some 



