Nov. 1, 1899.] Supplement to the " Tropical JgricuUurist." 
367 
Esparto grass, Sttpa tenacissima, for paper 
mauufacture and vegetable sponge. Luffa aegyp- 
tica, as substitute for bath sponges. The two 
species of palmetto and the Spanish moss for 
vec^etable hair are wholly produced in this country. 
As^to the sources of supply of these fibres, flax is 
imported chiefly from Belgium, Russia, Holland,., 
Italy, the United Kingdom of Great Britain and 
Ireland, and from Canada, China grass or ramie 
comes from China (in small quantities). Hemp is 
derived from Eussia, France, Belgium, Germany, 
Austria-Hungary, Italy, the Netherhiuds, and 
British East Indies (the latter in trifling quantity) ; 
jute from India, and Cuba bast from the West 
Indies. The imports of cotton are chiefly produced 
in Egypt and Peru, though small quantities may 
be derived from other countries. RalEa, used as 
agricultural tie bands, comes from Atrica. 
The sisal hemp supply is produced in Yucatan, 
small quantities being produced in Cuba and the 
Bahamas. Manila hemp is a product of the 
Philippine Islands, Cuba hemp being a trade 
variety. Mauritius or aloe fibre comes from Africa, 
and the source of supply of New Zealand flax is 
indicated by its name. Tampico, or Istle, is a 
Mexican product, and the Bahia and Para piassabas, 
or " bass " fibres, are collected from Brazilian 
palms. There are other species of bass (see Bass 
in Catalogue) derived from African palms, 
whicli formerly never came to the United States, 
and now, if at all, only in trifling quantities. 
Broom root is a Mexican product, the root of a 
tall, wiry glass. The two palmetto fibres are 
produced from uncultivated species of Florida 
palms, while the Criu vegetal is derived from an 
allied palm growing in Algeria. The vegetable 
hair from Spanish moss is prepared in South 
Carolina and other Gulf States, while coconut 
fibre comes from the East Indies. Esparto grass 
is produced in Algeria, Spain, and Portugal, and 
Tegetable sponge comes largely from Japan. 
Other commercial species that might be enumerated 
are imported in a partially prepared state or as 
manufactures. Such fibrous substances appear in 
the form of straw plait from Italy, Japan, and 
China chiefly, the eastern floor mattings and 
basketry from various substances. In this account, 
however, only the raw fibres are noted. The fibres 
produced in this country in commercial quantity 
are cotton, hemp, flax, palmetto fibre, and vegetable 
hair from Spanish moss. Hemp and flax produc- 
tion should be largely extended; jute production 
and the growth of sisal hemp, pineapple, and 
bowstring hemp are possible. Cane fibre can be 
produced in large quantities, and there are* doubt- 
less other kinds that might form the basis of heal 
fibre industries. The paper materials other than 
Esparto are not considered in this category. The 
native fibrous substances that might be employed 
in lieu of cellulose from our forest trees, for paper 
pulp, would make a long list, at the head of which 
might be placed the waste fibre from a million 
dcres of flax produced only for seed. A day is 
surely coming when the question of securing new 
pulp materials will present itself, and it is to be 
hoped that from the long list of native species of 
fibrous plants enumerated in this work something 
will be found that will supply at low cost a better 
paper material for common use than wood pulp, 
which has nothing to recommend it but avails 
ability of raw material and cheapness. 
THE PEOGEESS OF AGEICULTUKAL 
CHEMISTEY. 
The following is taken from an account of Prof. 
Maercker's address before the German Chemical 
Society, and gives his views with reference to 
Plant Food, Soils, and Manures, subjects of so 
much importance to agriculturists : — • 
In supplying nourishment to plants we must 
know what substances are necessary, and in what 
form and quantity they should be provided. 
Little progress was made in our knowledge of the 
subject till the quite recent introduction of the 
method of water-cultures of Sachs, Knoop, and 
Nobbe and the method of sand-cultures of Hellriegel 
permitted of the conduct of experiments in pure 
media, and thus rendered it possible to ascertain 
not only what substances are essential for plant 
life, but also the part played l)y each substance in 
the plant cell. Thus we know now that phos- 
phoric acid is essential for the formation of nitro- 
genous substances in the plants, because the albu- 
mens, which are of fundamental importance in the 
transformations of substances in plants, result 
from an intermediate phosphoric acid compound, 
as is indicated by the regular occurrence of lecy thin 
in protoplasm. Again, iron is an essential consti- 
tuent of chlorophyll and sulphur of albumen, and 
hence must be supplied to plants. The true func- 
tion of calcium was for long doubtful ; its action 
is now known to be of a medicinal character, 
since it serves to neutralize the poisonous oxalic 
acid, vrhich is always an intermediate product cf 
the oxidation of the carbohydrates. It was for- 
merly thought that calcium fulfilled some impor- 
tant function in the leaves, being chiefly found in 
the foliage of plants. Since, iiowever, the leaves 
are also the chief seat of the oxalic acid, this 
distribution of the calcium is easily explained. 
The part played by potassium has only within 
the last three years been explained by Hellriegel, 
who, by exact experiments with beet-root, showed 
that the amount of sugar in the beet stands in close 
relation to the amount of potassium provided for 
the plant. P. Wagner has made the interesting 
observation that the potassium may be partly 
replaced by sodium. 
The exact value of magnesium to plants is not 
yet well understood, but it appears to be of 
imi)ortance in the formation of the nitrogenous 
substances of seeds, as in these cousiderabl« 
quantities of magnesium phosphate occur, 
Nitrogen is an indispensable plant-food, for it is 
an essential constituent of albumen. 
In addition to the quantities of mineral sub- 
stances required by plants to enable them to 
exhibit a healthy growth, further quantities ara 
found to be essential to satisfy what has been 
termed, though not very aptly, the " mineral- 
hunger " of the plant. This is best explained by 
an example. E. Wolf found that for the produc- 
tion of 100 parts of oat-plant (dried), '5 parts of 
phosphoric acid was necessary, when the remaia- 
ing mineral substances were supplied in excess to 
