506 
The Mineral Theory. 
genuine organic matter. Mr. Lawes, however, lias not the slight- 
est desire to prove that the vegetable mould of Sprengel, or the 
organic extracts of De Saussure, are necessary ingredients of an 
efficient manure. On the contrary, all his experiments tend to 
prove that these substances, which cannot be produced in a ma- 
nufactory, are not necessary. What then does Mr. Lawes mean 
by organic manures ? 
The reader will be puzzled to learn that Mr. Lawes's theory, 
correctly expressed, is exactly the same which I published seven 
years before his definition of manure : — That the action of manure 
depends on two classes of bodies. The combustible part of plants 
derive their carbon, hydrogen, nitrogen, and oxygen, from car- 
bonic acid, ammonia, and water ; the incombustible parts of plants 
consist of phosphoric, sulphuric acid, potash, soda, lime, magne- 
sia, silica, iron ; that "stable manure^ the excrements of men and 
animals, do not influence vegetable life by means of their organic 
elements, but indirectly by means of the inorganic compounds 
which decomposition and slow combustion produce ; in conse- 
quence, therefore, of their carbon being changed into carbonic 
acid and their nitrogen into ammonia. Thus organic manure, 
consisting of parts or remains of plants or animals, may be re- 
placed by those inorganic compounds into which it resolves itself 
in the soil." 
The difference between Lawes's theory and mine is simply 
this — that he has borrowed the substance of mine and the terms of 
De Saussure's theory — that he calls ammonia, carbonic acid, and 
water, which I had called atmospheric food, organic manures ! 
There is still a question to be solved : — Were these three sub- 
stances classed by Lawes as organic manure generally understood 
by that name ? 
Now it is perfectly certain that neither De Saussure nor 
Sprengel employed the term organic to denote these three sub- 
stances, which they knew as inorganic. This denomination can 
therefore not be referred to them. There exist, moreover, no 
chemical works published before Lawes's definition (1847), in 
which they are classed as organic food or organic manure. It was 
consequently not generally understood that ammonia, water, and 
carbonic acid belong to the class of organic manure. The part of 
Mr. Lawes's theory which belongs to himself, is merely this 
erroneous nomenclature; I repeat, that the terms of his definition 
of manure he has taken from De Saussure, the essence of it is 
simply mine, but the manner in which he has tacked De Saussure's 
terms on to my meaning is purely his. 
I cannot think that the humblest teacher of chemistry in Great 
Britain would be content to accept a theory from a man who 
shows such ignorance of the first elements of chemistry as Mr. 
