20 



May 1st, 1894. 



A most interesting paper by Mr. Stuart Hills, on Local Lepidop- 

 tera was read, illustrated by specimens. 



Tuesday, Octobeb 2nd, 1894. 



The first meeting of the winter session was held, at which about, 

 sixtv 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 — from food 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 

 jenormous 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. If a 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, 0., 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. Bat 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. Either nitrates or ammonia must then be found by a 

 plant in the soil round its roots if it is to flourish. We will now 



