PROCEEDINGS OF SECTION B. 385 
TABLE OF COMPARISON 
(Calculated dry). 
Albuminoids,) Carbon- 
Fodder. “aang! | Saeeenee Weg mie PAH. 
Substances, | digestible. 
Lucerne “ee “ss 15°00 35°87 40°20 8:93 
Cabbage a a 14°17 | 67°02 10°76 805 
Barley Straw ee a10..|,  ¢Ls2 78°46 5°02 
Wheat Straw as 4°91 27°79 62°45 | 4°85 
Oaten Straw ... bs 318 | 44-62 45°92 | 6:28 
Oaten Hay ... eas 12:10 | 46°33 34-21 7°36 
Brewers’ Grains eee 19°37 | 50°31 23°79 6°53 
The annexed table shows at a glance the relative values of the 
foods. I have separated the woody fibre from the other 
carbonaceous matter, to show the amount of substance contained 
in the food capable of being assimilated and the amount which 
cannot be used up as a food by the animal. Lucerne, then, 
taking this and the high percentage of flesh-forming substances 
it contains into consideration, stands well at the top of the list of 
the fodders I have enumerated, and well deserves the reputation 
it possesses. I add the brewers’-grains, because they are used so 
largely as a cattle food wherever obtainable, and a comparison 
may prove useful. 
5.—NOTE ON THE ESTIMATION OF ALKALIES IN 
IGNEOUS ROCKS. 
By Joun Dennant, F.G.S., F.C.S. 
[ Adstract. | 
In the analysis of igneous rocks there are no more important 
bases to estimate than the alkalies, as the particular felspar 
present can thus be frequently determined. It is true that the 
microscope enables us to distinguish between the orthoclastic and 
plagioclastic felspars, or even to make further subdivisions with 
fair precision; but the chemical analysis is, after all, the most 
convincing test. Not seldom, there are macroscopic felspar 
crystals developed, of the same structure as the microscopic ones 
which constitute the ground-mass of the rock. 
x 
