HORTICULTURE AS A SCIENCE. 
35 
funnel, a few folded pieces of white blotting-paper to make filters, a small pestle and 
mortar of wedgewood ware with a lip, and a tumbler glass or two. These will 
form a very ample set of utensils ; the scales, mortar, two small jugs, and a few 
cups, would even be sufficient, as we have frequently proved. 
Process : — Collect a specimen of the loam to be examined, dry it in the sun, and 
take away any stones and pieces of wood that may be among it. Then weigh an 
ounce or half an ounce, troy or apothecaries' weight, — i. e. 480 or 240 grains. Rub 
the earth in the mortar so as to detach the gritty sand, and separate that by a sieve. 
Weigh the grit, and note the weight in grains : again weigh the fine siftings accu- 
rately, and make up any loss by a little more fine earth : then dry it in a saucer at 
a heat greater than that of boiling water. Weigh it while hot, and the loss will 
show the quantity of moisture which the soil retains naturally, however dry it may 
appear. This moisture it will attract again by being exposed to the atmosphere. 
Return the fine earth to the mortar, and rub it with water, gradually added, 
till a separation of parts be apparent ; then pour off the floating matter, and repeat 
the rubbing and washing with fresh water, till nothing but sand remain in the 
mortar : dry this sand by placing the mortar on the stock of a grate, or a warm 
iron plate. In the mean time all the waters being collected together in one jug or 
glass, will gradually deposit the fine particles, and the liquor will exhibit more or 
less colour, resulting from vegetable, or other manuring substances, contained in 
the earth. 
This earth and water should next be thoroughly stirred, and after standing 
quiet for two or three seconds, be poured into another vessel, slowly and cautiously, 
because some sand will have passed from the mortar which ought to be separated ; 
and this must be done by repeated washings and decantings. 
This second process will separate the fine matter of the soil, and the sediment 
can readily be collected by pouring off the water that appears quite clear, and then 
the remainder with the sediment, either into a plate or a paper filter previously 
weighed and placed in a funnel. In either case, the few particles remaining in the 
jug must be removed by a little more water, and added to the rest, or be wiped off 
by a piece of dry linen accurately weighed beforehand. The earthy sediment is to 
be dried first by slow evaporation, and then by a greater heat, equal to that which 
was employed in the first instance. All the dried products are to be weighed, and 
when three experiments of the kind have been completed, the operator may 
arrive at something like a correct conclusion. 
Thus, of 240 grains, there may be 120 of the Jine earths which we call clay, as 
they contain all the alumina of the soil ; of coarse sand, separated by sifting, twenty 
grains ; and of Jlne sand, left by the several washings, ninety. But there must be 
some loss, and ten grains is not much in 240. 
It is evident that we do not detect the chalk, iron, or pure clay, by this investi- 
gation ; nor can we hope to do so without chemical agency ; but we have discovered 
how to compare one soil with another, and now can form some notion of the errors 
