REPORT ON THE INDUSTRY OF MANURES. 
87 
the debris of manufactures in which horn, bone, hides, bristles, gut, and other organic 
and nitrogenous materials are used ; the spent animal or bone-charcoal of the sugar re¬ 
fineries, and other phosphatic residua ; the ammoniacal liquors of gas-works ; the alka¬ 
line wash-waters of soap, dye, bleach, and many other factories: in a word, several 
hundred forms of residua—nitrogenous, phosphatic, and alkaline—formerly cast away as 
worthless rubbish. 
These the respective patentees propose to subject to various processes, mechanical, 
physical, and chemical; such as, for example, in the case of liquors, to concentration by 
boiling down, or precipitation by chemical agency ; in the case of solid residua, to crush¬ 
ing, grinding, or other process of comminution ; or to chemical disintegration by powerful 
solvents, acid or alkaline, according to the circumstances in each case ; or to maceration 
in water ; or to torrefaction by fire; or to digestion, at low or high pressure, sometimes 
in moist, sometimes in dry or superheated steam. 
Several of the patents include recipes for mixing the products thus obtained with each 
other, or with products of a different origin, to adapt them (as the inventors allege) for 
special crops, or for peculiar soils. 
Many ^of these proposals possess merit; though a still larger number exhibit igno¬ 
rance on the projectors’ part; while a certain percentage almost seem to have been con¬ 
cocted with a view to profit by the ignorance of others. 
Superphosphate of Lime Manufacture. —First in importance, and nearly first also in 
chronological order, among the manure patents enrolled since the publication of Liebig’s 
book in 1840, stands the celebrated patent granted in 1842 to Mr. J. B. Lawes,* for con¬ 
verting tricalcic into monocalcic phosphate by means of sulphuric acid. The invention 
of this process, so far as it applies to the treatment of recent bones, is not claimed by 
Mr. Lawes, but belongs to Justus Liebig, who suggested it in his great work already 
quoted. As this suggestion has become the foundation of the modern industry of ma¬ 
nures, and its authorship has been the subject of controversy, the Reporter feels bound to 
record, in the foot-note below, Liebig’s own words on the subject.! 
The great merit of Mr. Lawes consists, first, in his having extended the application of 
sulphuric acid to phosphates of mineral origin, such as apatite, and to the fossil bone 
phosphate known as coprolite; and, secondly, in his having devised means and appli¬ 
ances for carrying out the manufacture on an industrial scale. Those upon whom it has 
devolved to organize a new industry, and to overcome the difficulties that spring up, un¬ 
foreseen, at every stage of such a work, will know how to appreciate at their just value 
Mr. Lawes’s services in this respect. Indeed, in his double capacity, as a manufacturer of 
manures, and as an indefatigable experimentalist on their effects, Mr. Lawes merits re¬ 
cognition as one of the most active promoters of agriculture now living. Nor would it 
be just, in such a mention, to overlook the large share of service rendered by Dr. Gilbert, 
the able coadjutor of Mr. Lawes in the experimental and analytic department of his 
labours. 
Mr. Lawes appears to have made his first essays in the manufacture of superphosphate 
in 1841-2 ; and, on the success of these experiments to have begun his great manufac¬ 
tory at Deptford in 1843. Many similar works have since sprung up, and the manufac¬ 
ture has grown to enormous magnitude. Mr. Lawes himself produces 18,000 to 20,000 
tons of superphosphate annually ; and the total yearly production of superphosphate in 
Great Britain is estimated by him as ranging from 150,000 to 200,000 tons. 
' * Lawes (J. B.), Patent No. 9353, May 23, 1842. 
f “ The form in which they [bones] are restored to a soil does not appear to be a matter 
of indifference. For the more finely the bones are reduced to powder, and the more inti¬ 
mately that they are mixed with the soil, the more easily are they assimilated. The most 
easy and practical mode of effecting their division is to pour over the bones, in a state of 
fine powder, half of their weight of sulphuric acid diluted with three or four parts of water, 
and after they have been digested for some time to add 100 parts of water, and sprinkle this 
mixture over the field before the plough. In a few seconds, the free acids unite with the 
bases contained ha the earth, and a neutral salt is formed in a very fine state of division. 
Experiments instituted on a soil formed from gramvacke , for the purpose of ascertaining the 
action of manure thus prepared, have distinctly shown that neither corn nor kitchen-garden 
plants suffer injurious effects in consequence, but that, on the contrary, they thrive with 
much more vigour.”— £ Organic Chemistry in its Application to Agriculture and Physio¬ 
logy/ PP-184-5. 
