THE FARMERS' REGISTER. 



349 



air. From experiments which bore some analogy i 

 to the process ol ve<];etaUon, he had shown thai 

 a much greater weight was uil<tMi u|) by chemical 

 substances, having an allinily tor carbonic acid, ; 

 than was required lor plants growing in iho same 

 time ; without denymg the use of humus, or the i 

 ingredient consiituiing vegetable mould, which 

 exists m almost all good sods. In connexion j 

 with the subject, he had shown, that, if we ex- 

 amine tlie constitution of plants, we sliali find i 

 almost every one ol' their elements, such as woody i 

 fibre (/(gni'/i,) starch, sugar, larmic and tartaric] 

 acids, and the essential oils, contain less oxygen j 

 than carbonic acid, with which the air lurnishes ' 

 them; and, consequently, that, in the act ol ' 

 taking them in, oxygen must be given out. He j 

 had mentioned this, m relerence to the main ques- 

 tion — the maintenance ol' the puriiy ol the at- 

 mosphere, lor if we suppose, from the respiration 

 of man and animals, and the combuslion of im- 

 mense quantities of carbonaceous matter (amount- 

 ing, perhaps, to thousands ol' tons in this town 

 alone,) that the quantiiy of carbon in the atmo- 

 sphere had gone on increasing, and that of oxygen 

 decreasing, and that thus, after a given time, the 

 materials of which the atmosphere is composed 

 would become unfit lor the support of life — we 

 should see that, by this beautilul arrangement, 

 the decomposition of carbon and the giving out 

 of oxygen, the purity of the air was constantly 

 maintained; and that the direction given to the 

 winds by ditierent temperatures also tended to 

 equalize the purity as well as the temperature of 

 the air throughout the globe. He had shown, 

 that we need not look very far lor the sources of 

 hydrogen and oxygen, inasmuch as oxygen might 

 be taken in as a constltueni of the air, or might 

 exist as a constituent of watt r, in combination 

 wiih hydrogen, and hydrogen is necessarily taken 

 in I'rom the water, winch is abundanily provided 

 lor plants both in rain and in the dews which 

 occur in the absence ol rain. We will now 

 (continued Mr. Ransome) proceed to a conside- 

 ration ol' what other materials are lound to be 

 contained in plants, and, in fact, Ibund to be 

 essential to their growth. But we have still one 

 other substance to rank with those already con- 

 sidered — nitrogen or azote, the fourth principal 

 element of plants. Some are disposed to think 

 that this does not enter materially into the com- 

 position of a plant, except in the case of some 

 poisonous plants, or those which possess strong 

 medicinal qualiiies ; but a [qw words only are 

 necessary to show that, unless plants did contain 

 this element, animals could not derive much nu- 

 triment Irom them. It has long been known, 

 that if dogs are led upon pure sugar, which is ac- 

 knowledged to be nutritive when mixed with 

 other things, they fall into a kind ol consumption, 

 lose flesh and strength, and ultimately die with 

 symptoms of emaciation and decline. Sugar is 

 one of those substances which contains no azote 

 or nitrogen. On the other hand, we have whole 

 tribes of men and animals who live upon nothing 

 but vegetables ; yet the bulk of their muscle or 

 flesh contains a large proportion of azote. Whence 

 can that be derived, unless the Ibod they take 

 contains a large portion of it, or we consider man 

 as possessing the power to assimilate the gaseous 

 elements around him? But the fact is, they do 

 not take in azote from the atmosphere, and they 



would die unless I hey were provided with some- 

 thing as an aliment containing azote. We shall 

 see ihat, although sugar and starch exist in tlie 

 leaves ol plants, yet every particle is surrounded 

 by a thin lamma, of a substance which contains 

 azote, and it is owing to this that many changes 

 lake place spontaneously, or by means ol'the root. 

 The simple o|)eration ot ferineniation takes place 

 from the gluien, which contains a quantity of 

 azote, reading upon the sugar which it invests ; 

 and we shall see many instance s in which che- 

 mical changes are effected through the insirumen- 

 taiity of the azotous principle which accompanies 

 the other more truly vegetable principle. A com- 

 putation was made by Boussinguah, a I^'rench 

 chemist, that hay contains one hundredth part of 

 iis weight of azoie. Hence we see the source 

 of the nutriment of cattle led on grass. Wheat 

 contains even a larger quantity ; and, in propor- 

 tion to the nutritious quality of the wheat, shall 

 we find the greater quantity of azote. And upon 

 this depends the practical application of chemistry 

 to the art of culture, — viz. the providing a plant 

 with substances which will give out azote to it ; 

 for such is the difference in wheal, that some only 

 contains 3| per cent, of gluien, whereas other 

 wheat, provided by the care and foresight of the 

 farmer, with proper composts, has this quantity 

 of 3^ per cent, of gluten increased tenfold, or to 

 35 prr cent. We also find, that if a horse, for 

 example, be fed upon potatoes (which it will eat 

 readily enough,) it is unfit lor its work, and loses 

 strength, and spirit ; because the potato is a 

 plant which contains but little azote. In the East 

 Indies people live very much upon rice, which 

 contains but littJe azoie; and, in order to get a 

 fair proportion of this principle, they have to lake 

 a larger quantity of food. It is singular enough, 

 that one of the articles in daily use in most fami- 

 lies should be a substance containing a large 

 quantity of azote — viz., coffee. The cafine, or 

 active piinciple of coffee, contains mare azote 

 than almost any other known body. I was in 

 hopes to have exhibited before you this evening 

 a lew proofs that some plants contain azote ; but 

 unlbrtunately it has very intractable qualities ; 

 and, though it w6uld put out a light, it would not 

 display any very active properties. The form in 

 which it is best known in combination is that of 

 ammonia, or the gas which is the pungent ele- 

 ment of the sails contained in thesmelling bottle. 

 Ammonia is known to contain a certain propor- 

 tion ol azote, represented by the Ibrmula N^, H-^, 

 or one proportion of nitrogen or azo:e, with three 

 proportions of hydrogen ; and these two, combined 

 in these proportions, constitute ammoniacal gas. 

 This gas is Ibrmed under many circumstances, 

 in the decomposition of vegetable and animal sub- 

 stances, and in the elimination of hydrogen : and 

 ilieretbre we may naturally expect, that, fi-om the 

 immense masses of putrilying matter upon the 

 surface of the earth, the relics of former genera- 

 tions, ammonia must be given out, into the atmo- 

 sphere. Most of us were struck with the very 

 small proportion of carbon or carbonic acid (bund 

 in the air, only one-thousandth part of its bulk ; 

 yet I showed you also, that when coral reels are 

 tbrmed in the ocean by myriads of animalcula. 

 these little animals contrive to abstract from the 

 water sufficient carbonate of lime, to form future 

 islands ; and yet the quantiiy of lime in sea-water 



