50 QUEENSLAND AGRICULTURAL JOURNAL. {i Juny, 1902. 
Mr. J. W. Lex, of Zillmere, then read the following paper on :— 
THE ATMOSPHERE. 
[By J. W. Ler, Zillmere.] 
GeNTLEMEN,—The subject of the paper I purpose reading to this ConferenceTis 
the atmosphere—its composition and its action on soils, plants, and animals. I am 
convinced, gentlemen, that this subject is one of considerable importance to all those 
engaged in the tillage of the soil as agriculturists or horticulturists. 
I may state that the atmosphere was the first agency employed to produce a 
soil capable of tillage,and of bringing forth the fruits of the earth. But I fear £ 
shall not be able to more than touch the fringe, so to speak, of this subject in the time 
allowable in this Conference. I shall, however, in the first place, endeavour to explain 
what the atmosphere is composed of, and I may state, in passing, that of the three 
materials forming our globe and its envelope—namely, solids, liquids, and gases, 
as the atmosphere—the latter is by far the least understood by the general public, 
and the reason no doubt is that the two former make themselves more forcibly known 
to us through our senses of sight and touch. We can see water, and we can direct its 
course. We can handle the solids of our globe, and feel their resisting powers in 
loughing and digging. But the atmosphere appears to be beyond our grasp. I have 
just stated that the atmosphere is one of the three materials which belongs to our 
globe, and I desire to press on you this fact: That the atmosphere is a material 
substance, though we cannot seeit. It has force; it can be measured and weighed— 
one cubic foot weighs 527 gr. or about 1} 0z., and is 715 times lighter than water. 
The pressure of this atmosphere on the surface of the earth is 15 1b. to the square 
inch of surface. This fact I wish you to bear in mind, as I shall have to refer to it 
again as an important feature in connection with the tillage of our land. Many other 
interesting statements might be made in reference to atmospheric influence in, 
connection with tornadoes and cyclones, which are merely the atmosphere in a rage— 
in other words, wind is but the atmosphere in motion. Having stated in my previous 
remarks that the air is a material substance, I shall now proceed to consider what itis 
composed of, and how these components act on the soil, on plant, and animal life. The 
air around us is composed of a variety of gases, the chief of which are—lst, nitrogen; 
2nd, oxygen; and, incidentally, carbonic acid gas, ammonia, nitric acid, and watery 
vapour. 
E All these gases are needed in the atmosphere for the support of both plants and 
animals, and also for the purpose of assisting in reducing the soil from an insoluble 
to a soluble condition. Some of the above-named gases are in the air in very small 
quantities, nitrogen and oxygen occupying by far the largest space—namely, nitrogen 
about four-fifths, and Oaks one-fifth ; and the rest of the gases named are presentin | 
very small proportions indeed, but are so wonderfully blended and arranged by the 
Supreme Being that the greatest harmony prevails and the utmost benefits are 
conferred on both animal and vegetable life. 
I shall now attempt to explain some of the characteristics of these gases. Ist. 
Nitrogen, which occupies four-fifths of the atmosphere, is generally known_for its 
inactive or indifferent qualities, and in its gaseous form appears chiefly to exist for the 
purpose of curbing the impetuosity of its too active companion, oxygen gas. But in its 
solid form it is one of the most important ingredients in the formation of plants, 
producing food for both man and beasts, and the value of such foods is generally 
estimated by the proportion of nitrogen they contain. 
We shall next consider the oxygen gas, found in the atmosphere in the proportion 
of one-fifth of the whole. This is the most active and powerful agent in the air. To 
relate all the manifold operations of Nature in which oxygen is employed would 
take up too much time and space. I shall, therefore, only refer to a few which most 
interest those engaged in the tillage of the soil. Se 
In the first place, it is a fact that this gas, in company with that of carbonic acid, 
may be truly looked upon as being the father of our soils, for it was this gas that first 
penetrated the primitive rocks by its silent but irresistible power, reducing them to the 
small particles we call soils. And this work is still going on every day, grinding 
even those particles to a finer powder, and thus liberating, slowly but surely, the plant 
food they contain. As a proof of the power of this gas, I might refer to what some of 
us, no doubt, have often seen in the old land—viz., the old castles and cathedrals, 
some of which have been standing for some 600 years. We have seen the shattered 
or shaley condition of the outside of those buildings. This, I may state, is the work 
of this powerful disintegrating agent, oxygen gas. Wemay think it strange that a 
mere gas can produce such effect upon even the hardest granite rocks, and yet we can 
