of the present day bears
about the same relation to genuine old-fashioned guano, as leached ashes
do to unleached, or as a ton of manure that has been leached in the
barn-yard does to a ton that has been kept under cover."

"True, to a certain extent," said the Doctor, "but you must recollect
that this 'guaranteed' guano is now sold by analysis. You pay for what
you get and no more."

"Exactly," said the Deacon, "but what you get is not so good. A pound of
nitrogen in the leached guano is not as available or as valuable as a
pound of nitrogen in the unleached guano. And this fact ought to be
understood."

"One thing," said I, "seems clear. The Peruvian Government is charging a
considerably higher price for guano, in proportion to its actual value,
than was charged 20 or 25 years ago. It may be, that the guano is still
the cheapest manure in the market, but at any rate the price is higher
than formerly--while there has been no corresponding advance in the
price of produce in the markets of the world."

POTASH AS A MANURE.

On land where fish, fish-scrap, or guano, has been used freely for some
years, and the crops exported from the farm, we may expect a relative
deficiency of potash in the soil. In such a case, an application of
unleached ashes or potash-salts will be likely to produce a decided
benefit.

Clay or loamy land is usually richer in potash than soils of a more
sandy or gravelly character. And on poor sandy land, the use of fish or
of guano, if the crops are all sold, will be soon likely to prove of
little benefit owing to a deficiency of potash in the soil. They may
produce good crops for a few years, but the larger the crops produced
_and sold_, the more would the soil become deficient in potash.

We have given the particulars of Lawes and Gilbert's experiments on
barley. Mr. Lawes at a late meeting in London, stated that "he had grown
25 crops of barley one after the other with nitrogen, either as ammonia
or nitrate of soda, but without potash, and that by the use of potash
they had produced practically no better result. This year (1877), for
the first time, the potash had failed a little, and they had now
produced 10 or 12 bushels more per acre with potash than without,
showing that they were coming to the end of the available potash in the
soil. This year (1877), they obtained 54 bushels of barley with potash,
and 42 bushels without it. Of course, this was to be expected, and they
had expected