430 
Supplement to the " Tropical Agriculturist." [Dec. 1, 1694. 
Bacteroids and rDoMmhetelee wert ttfcotw time 
only associated with the lffgOBiinoae, bat further 
investigations have brought to light the fact that 
there are other plants which are aleo capable of j 
fixing nitrogen in this way. la oat November 
number when writing of useful weeds we referred 
to the action of tit.M'.iri'i media (It caryophylla- i 
cous weed; as an importer of nitrogen into the soil. | 
Dr. Fream writing in the Royal Agricultural 
Journal on the German researches into this 
subject, says : - - ' I:i 18!) I the experiments WCjra 
extended to ; ! itttB other than leguminous species 
Plants bul >ugAug to several different natural ord eta, 
as well as peas representing the p ipilionaceous 
division of leguniinosaj, were grown under 
similar conditions i Ill'CHlghout. 
These diverse plants were: — 
Jerusalem artichoke, — nat. ord. Composite. 
Oats, — nat. ord. Or ami tie®. 
Tobacco, — nat. ord. Solanoip ■ 6. 
Mustard, — nat. ord Crucifene. 
Cress „ „ 
Giant spurrey, — nat. ord. Caryophyllacere. 
Two series of experiments were made in 1891. 
In the first series the surface; of till the Soil 
became covered, to a greater or less extent, with 
inferior green plants, amongst which were re- 
cognised certain Mosses (Bryuiu, Leptobryum) and 
certain Algfe (Conferva, O.-cillai ia, Nitzschiu). 
In all these eases absorption of nitrogen took 
place, save in two instances in which the develop- 
ment of these humble forms of plant-life was 
very feeble. In one case in which none of the 
higher plants were present, the soil became 
clothed with a notable quantity of the lover 
green plants, and advantage was taken of this 
circumstance to determine what proportion of the 
absorbed nitrogen had been taken up by the plants, 
and what proportion by the soil. It was found 
that all the nit roge i tint had been gained was 
accounted for by the plants, the underlying soil 
not showing any gain. 
In the second series of the experiments of 1801 
measures were adopted to prevent the appe i ranee 
of the inferior green plants. This was effected 
by covering the soil, after the seed, had beeu 
sown, with a thin layer of calcined quartz-sand, 
upon which nothing could grow (Mosses and 
Algoe possess no roots). In this series of experi- 
ments there was no fixation of free nitrogen, 
neither by the s i! nor by the plants other than 
peas. 
The investigators arrived at the following con- 
clusions : — 
1. The Leguminosre (division Papilionacose), 
as represented by peas, are able lo draw largely 
upon the free nitrogen of the air for purposes 
of growth. 
2. Some of the inferior green plant ; possess 
the same properly. 
3. In the conditions under which the experi- 
ments were conducted, bare soils. — that is, soils 
devoid of any apparent vegetation — failed to fix 
free nitrogen in any measurable quantity. Oats, 
mustard, cress, spurrey likewise failed to fix the 
free nitrogen under conditions identical with 
those in which peas fixed it abundantly. 
This subject of soil-inoculation, or, as it Las 
also beeu spoken of, soil-vaccination, though 
every year sees more light thrown on it, lias un- 
doubtedly to be worked out a great deal more. 
We have yet to know why it is that certain plants 
can act, and others cuuuot act, as fixers of 
nitrogen in the soil; and further we ha\e yet to 
know some convenient method of distinguishing 
the one class from the other. The appearance of 
tubercles on the roots is not an absolute guide 
i a discovering the dedred plants, fdnce we have 
been th.it tubercles m ay not be found, under 
certain circumstances, on plauts which uuder 
other circumstances develope them- We can but 
speculate as to to Grecillm*, Albizzi'm aud 
Toons (these families belonging to three different 
botanical orders) and other plants being nitrogeu 
fixers, ami attribute the beneficial iuliuence which 
they appear to have on tea to their action as 
such, when in fact there may be other chemical und 
mechanical influences we wot not of, which the) 
\ rt when intorplunted on tea estates, Still 
tiie matter is well worth looking into, and specula- 
tion may, as it has often done, lead to useful 
discoveries after prolonged research ; and in the 
interests of all agriculturist-, from the humble 
peasant to the extensive tea proprietor, we trust 
that science will before long ieveal the secrets 
involved in this subject of soil inoculation or 
vaccination, so that cultivators of land will 
soiu bj iu a position to control und impress 
into their service the ne .vly-disc ivered forces 
which are capable of fertilizing the soil. 
NEW AM) OLD PRODUCTS. 
A new product has a charm, even from 
the very fact that we are little acquainted 
with its iiabits, and owing to the difficulties of 
producing a paying crop under given circum- 
stances. There is, of course, always an interest 
iu what is a novelty. Out of a dozen new 
species of plants that may be introduced into a 
country, we may say that hardly a single one finds 
a permanent place in its vegetable economy. It 
is important, however, that all should have 
a fair trial, or it would be impossible to say 
which one will prove a success in the long run. 
Hence every new product that has auy likelihood 
of growing in our soils deserves attention. It is 
of greater importance iu one respect to look to t he 
development of existing products thau to the 
introduction of new aud foreign ones. There 
are many products which are now uncared for, 
or which, grown in a careless way, do not pro- 
duce a rumunerative crop, but which could with 
a little extra attention be made a paying industry. 
Systematic work is essential if anything like 
success is to be attained iu the development of 
some of the products which are already found 
in the Island, and which are not properly cared 
for. Among these products we may place cotton 
as a very good example. Some time back a stir 
was made about cotton cultivation on the starting 
of the Ceylon Spinning aud Weaving Co. On 
experimenting with the product, however, the 
excitement about cotton subsided after on3 or 
two season?, — not that the experiments were 
failures iu all cases, for in some districts the 
plant throve well. There was, however, one thing 
wanting, and that was experience in the manage- 
ment of the crop ; and if cultivation was persisted 
in, this experience would iu the course of things 
have been gained by the cultivators. In India a 
villager growing cotton would as a matter of course 
