and interesting fact, that the bland atmospheric air which we breathe, 
and the corrosive acid, known familiarly as aqua-fortis, contain che¬ 
mically, the same constituents, namely, azot or nitrogen, and oxygen. 
In the air, the proportions of azotic gas and of oxygen gas are about 
79 parts of the former, and 21 parts of the latter, both by measure. 
In nitric acid they are calculated to exist in the proportion of 26 
parts by weight of nitrogen, to 74 parts of oxygen. 
I shall reserve what I have to remark upon the qualities of the 
various substances or products above described, and the agencies in 
which they are employed; because I conceive that elementary in¬ 
struction is more effectually conveyed by the exemplification of facts, 
than by copious, dry detail. 
ARTICLE II. 
OxN THE CULTURE OF SEA-CALE (CRAMBE MARATIMA). 
BY MR. MOSES BRISTOW, 
\ 
Gardener to C. G. Munday , Esq. Burton , Leicestershire. 
This plant, although a native of this country, and found growing in 
the sand on most of our southern shores, has not, so far as can be 
traced, been in use as a dinner vegetable more than a century. The 
first account of its being sold in the market is in 1753. About 1767, 
Dr. Lettsom cultivated it at Grove Hill, and brought it into general 
notice in the neighbourhood of London. The Romans do not appear 
to have attempted its culture in their gardens, though they made use 
of it on occasions of long voyages-at sea, storing it in old oil barrels, 
which were kept air-tight. In Ireland, this plant was cultivated in 
the gardens, in the neighbourhood of Dublin, about 1764. When 
the seeds were sown, they covered them with a good thickness of 
gravel; and it was then the practice to boil it in two separate waters, 
it being supposed to be impregnated with a considerable portion of 
salt. There are now but few gardens of importance, either in this 
country or Ireland, where Sea Cale is not grown. It is a plant of 
very easy culture, and is always eaten in a blanched state. Manv 
different methods have been practised, most of which, in a greater or 
less degree, have answered. Where there is no intention of forcing 
it early, many persons cover the stools pretty deep with sand or coal 
ashes, placing a stick against each root, as a guide to cut the young 
shoots, previous to their appearance above the surface. Others mix 
an equal portion of well decayed manure with the coal ashes, and in 
