20 
May Isr, 1894. 
A most interesting paper by Mr. Stuart Hills, on Local Lepidop- 
tera was read, illustrated by specimens. 
Turspay, Ocrosrr 2nd, 1894. 
The first meeting of the winter session was held, at which about. 
sixty were present. The President, Dr. Thomas Eastes read the 
following paper on—- 
PEAS, BEANS, AND BACILLI. 
I have gone somewhat off the beaten tract in the choice of a 
subject for this evening's paper, but I hope it will not be found 
altogether devoid of interest to my audience. In comparing a full- 
grown animal with itself in its earliest weeks of life, we see an 
enormous increase in bulk, in the actual amount of flesh, bone, and 
blood of which it consists. All this increase of material is obtained 
in two ways—tfrom fvod and air; by feeding and by breathing; and 
excepting the oxygen obtained from the air by respiration, all the 
rest is practically supplied as food, so that, again exceptmg oxygen,, 
a man has obtained by swallowing and digesting all the material 
that has gone to increase his weight since he was a child. When 
we turn to the Vegetable Kingdom and look at an oak and then at. 
an acorn, we cannot but be struck by the consideration of the- 
enormous amount of material that has to be obtained and assimi- 
lated one way and another for that acorn to become an oak. A 
plant, when once it has emerged from its seedling condition, obtains. 
all that is necessary for its growth in two ways—by its leaves and 
by its roots. Ifa plant is analysed chemically, it is found to con- 
tain many elements variously combined, but a large proportion of it. 
is made up of four elements, C., O., H.,N. (Carbon, oxygen, 
hydrogen and nitrogen). Roughly speaking, the carbon is obtained 
from the carbonic acid in the air by the leaves and some of the 
oxygen, and the rest of the oxygen and the hydrogen chiefly from 
water by its roots. But what about the N.? (Nitrogen) The air 
which we breathe, and which surrounds the leaves of plants, consists 
of about four-fifths of N., and it would seem very natural and simple 
that this should supply the necessary amount of N. for plant life 
and growth, but it does nothing of the sort. It is established as an 
axiom in vegetable physiology that plants cannot make any use of 
the free N of the air. There are two kinds of compounds contain- 
ing N., which especially contribute the supply of this element to 
plants, viz., nitrates or salts of nitric acid, and ammonia and its 
compounds. Hither nitrates or ammonia must then be found by a 
plant in the soil round its roots if itis to flourish. We will now 
