CHEMISTRY OF HORTICULTURE. 
103 
RUSSELIA MULTIFLOEA. (Many-flowered Russelia.) 
Class, DiDYNAMiA. Order, Angiospermia. Nat. Order, Sgrophulariace^. (Fig-worts, Veg. King.) 
Generic Character. — Calyx deeply five-parted ; seg- 
ments acuminately tubular. Corolla tubular, swollen, and 
widened at the top ; limb bilabiate ; upper lip emarginately 
two-lobed ; lower lip tripartite ; segments nearly equal ; 
palate convex, bearded. Stamens four, didynamous, in- 
closed ; cells of anthers spreading. Stigma undivided. 
Capsule inclosed in the calyx, nearly globose, attenuately 
beaked, two-celled, two-valved ; vaZw* bipartite ; placentas 
central, at length free. Seeds numerous, small. 
Specific Character.— PZani a shrub 4 to 6 feet high. 
Stem quadrangular, smooth. Leaves opposite, ovate, acu- 
minated, seirately crenated, glabrous. Raceme terminal, 
many-flowered, verticillate. Pedtmcles cymose. Flowers 
scarlet-rose. Calyx green. Corolla nearly an inch long; 
limb divided into five ovate spreading segments. Stamens 
four, two of which are longest. 
Authorities and Synonymks. — Russelia, Jac. Amer. 178 . 
R. multiflora, Sims in Bot. Mag., t. 1528. 
This plant was introduced to Britain so long ago as 1819 from South America, where it 
was discovered growing in a mountainous district between Vera Cruz and Mexico. 
To grow it well, an atmosphere intermediate between the stove and greenhouse is the 
best. It should be potted in good sandy loam, mixed with about one-third peat, and a 
little sand. Give plenty of pot-room, and when growing a good supply of water. It is 
advantageous also to syringe frequently in fine weather, to prevent the appearance of insects. 
Propagation is effected by cuttings of the half-ripened wood, planted in pots of sand, 
and placed under a glass in heat. 
The generic name is given in honour of Dr. Alexander Russel, an English physician 
who resided for some years at Aleppo, and published an account of his observations upon 
the Natural History of that place, in the year 1756. 
CHEMISTRY OF HORTICULTURE. 
By John Towers, Esq. 
(Continued from Page 135.) 
Nitrogen, formed on the Greek noun nitron {yirpov), and the contraction gen {yev), the 
generator of nitre or saltpetre. This aeriform fluid, or gas, is in bulk the chief constituent 
of atmospheric air, as will be made to appear in its proper place. The terms Nitrogen 
and nitrogenous are now in the mouth of every scientific agriculturist, being applicable to 
all those substances which are proved to afford the strongest nutritive principles of plants 
and animals. In passing on to the description of the qualities of this interesting element, 
it may be remarked, that before the refined processes of modem organic chemistry had 
revealed the highly nutritious and sustaining properties of nitrogen, chemists had assigned 
to it the terms Azote and Azotic Gas, derived from the privative letter a, and the Greek 
noun zoe (fcor}) life, (destructive of life,) because life-sustaining as it is, when in combination 
with atmospheric air, it was found, when pure, to be fatal to animals which breathe. 
This gas was first discovered or rather recognised as a distinct aeriform fluid, by Doctor 
Rutherford, of Edinburgh, in 1772 ; but he gave it no name and mentioned few of its 
properties. Dr. Priestley discovered it also, and in the same year — 1773 — described 
several of its qualities in the Philosophical Transactions. Thus, as in the discovery of 
oxygen, two philosophers laid claim, with equal right perhaps, to the recognition of the 
elements of that air which had been the supporter of breathing life from the period of the 
creation of man. Strange, that nearly six thousand years of recorded time should have 
elapsed, and the world remain in ignorance of facts so stupendous ! 
Our documents are numerous, and their authorities so unquestionable, as to admit of 
little comment. Some of these must now be cited in the order wherein they occur : — 
1. Dr. Priestley obtained azotic gas by exposing a known quantity of atmospheric air to 
a mixture of sulphur and iron-filings, moistened into a kind of paste. Chemical action 
is thus induced, the filings attract the oxygen of the air, combine with it, and set the 
