228 
CULTURAL CHEMISTRY. 
Brande says, by evaporating a pint of sea-water, we obtain — 
Common Salt . 
Chloride of Magnesium 
Sulphate of Magnesia 
Sulphate of Lime 
Grains. 
180-5 
23-0 
15-5 
7-1 
226-1 
And this water, according to Murray, contains previous to evaporation — 
Grains. 
Common Salt 180-5 
Muriate of Magnesia . 18-3 
Muriate of Lime ......... 5"7 
Sulphate of Magnesia 21-6 
226.1 
Traces of chloride of potassium, of iodine, and bromine, may also be found in it ; 
and, according to Dr. Marcet, " of triple sulphate of magnesia, and potassa, and of 
muriate of lime." 
Here then, to adopt chemical language, we obtain, as bases, soda, potassa, 
magnesia, lime, and perhaps ammonia; and as combining acids or neutralising 
elements, chlorine, hydrochloric (muriatic) acid, sulphuric acid, carbonic acid, 
bromine and iodine. Attention to these constituents is of the utmost moment, as is 
the great fact — one which every geological discovery tends to prove — that the whole 
surface of the globe was originally "submerged in water, and consequently that all the 
saline matters which the earth contains, in whatever situation they exist, whether in 
rocks or earths, had their origin in the water of the sea. 
Guano, as imported pure, is the type of all our modern empyrical compounds ; 
it is the product of birds which feed upon fish, and deposit their ordure upon sea- 
rocks. Keasoning upon the composition of this remarkable and most comprehen- 
sive substance, and very probably upon that of sea-water itself — " Chemical 
analysis " (to borrow Mr. Johnston's words) " explained the composition of Guano," 
and he " declared that it could be imitated at a reasonable rate, and published 
experimental recipes for compounding artificial mixtures to be tried against it. 
Immediately, half-instructed men — supposing the practical conclusion already arrived 
at, which more cautious men were only beginning to seek for- — hurried into what 
appeared to them a sure and easy way of making money. Artificial guanos and 
prepared manures, qualified to do everything, appeared in the market," &c, &c. 
Some of these we have known and tried, but as they belong chiefly to agriculture, 
it will not be pertinent to dwell long upon the subject. One of them was seriously 
offered to the attention of gardeners, and met with occasional approbation ; it is 
called Potter's Guano, and contains salts which are found in many plants, and to a 
certain extent, in some loams. The best preparation of an. artificial manure that 
came under personal observation, consisted chiefly of a very large proportion of fine 
bone-dust, which if pure, contains about half its weight of phosphate of lime, from 
