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The commercial importance of esparto grass
June, I914.]
CURRENT TOPICS.
7OI
Absorption of Gases by C o a l . - - F . LEPR~NcE-RINGUET. (Comptes Rendus, clviii, 573. ) - - S u c h gases as fire-damp, carbon dioxide, air, oxygen and methane, at pressures ranging from 0.25 to 80 atmospheres, were absorbed by coal to a much less extent than by charcoal, but in both cases the absorption was of the same general character; a state of equilibrium existed for each temperature and pressure, and the absorption markedly decreased as the temperature rose; the increased absorption with increased pressure was rapid at first but gradually tended to a limit. Equilibrium was reached very slowly, and in the case of carbon dioxide especially, evolution of the absorbed gas, however slowly effected, was spasmodic. Results of the ~ame order of magnitude were obtained with coals of widely different composition and size of grain ; they afforded no explanation o f the la'rge evolution of fire-damp observed in very gassy mines. Active Nitrogen. E. TIEDE and E. I)OMC~(E. (Bet., xlvii, 420.) - - B y means of a jointless glass apparatus in which Lindes' commercial nitrogen was passed over copper heated electrically to a temperature measured by a thermo-couple, it was shown that the afterglow was suppressed unless the nitrogen was purposely contaminated with oxygen, provided that the temperature and pressure were such that no dissociation of copper oxide took place. On raising the temperature beyond a limit depending on the pressure, the glow was restored. The phosphorescence of sulphur, iodine, sodium and thallium chloride, observed on heating them in nitrogen which has been subjected to the action of the electric discharge, and attributed by Strutt to the presence of active nitrogen, was similarly suppressed in the absence of oxygen.
The Commercial Importance of Esparto Grass. C.J. KocH. (Tropenpttan~er, xviii, 5 9 . ) - - T h e esparto plant grows best on mixed limestone and gravel soils; its natural region lies between 320 and 4 I° N. latitude, but it is capable of resisting considerable variations in temperature and is found at altitudes up to 30o0 feet. The leaf ranges in length from 3 ° to 7 ° cm., attaining I m. under exceptional circumstances. It is pale green while growing but becomes yellow on drying; it rolls up when drying, attaining its cylindrical form at the ripening stage. About 2oo,o0o tons of the grass are imported ahnost wholly by England ; the quantity has remained stationary for 15 years, a decline from one source being balanced by increased importations from other sources. If the leaf is harvested before maturity the quality of the fibre is very inferior, yielding a semitransparent paper. In most districts the use of the knife is forbidden ; a tuft of grass requires 8 to ~5 ),ears before it becomes productive and may then be " pulled " annually for 3 ° to 50 years. The best time for pulling is the autmnn ; in most countries a close season is fixed by regulation during the earlier months of the year. The
702
CURRENT TOPICS.
[J. F. I.
harvested grass is stored and dried for a considerable time before packing for shipment; the hydraulic pressed bales weigh about 221~ lbs. per cubic foot. The majority of German paper makers are not interested in the grass, partly through unfamiliarity, partly owing to difficulties in procuring freights. Freights from Algiers and Oran run 'about 28/- per ton for Hamburg and 24/- for English ports. The area under esparto in Algeria is about 2,8o0,000 acres, of which three-fourths are in the department of Oran. Regulations as to season of cropping are in force, also certain zones are reserved as a protection against sand-drifts. Exports from Algeria were lOO,788 tons in 1911 and 116,632 tons in 1912, average price 52/- per ton; exports from Tunisia were 5o, I97 tons in 1911, average price67/per ton. Increases from these countries in recent years have taken place at the expense of the Tripoli trade, now practically ruined by war and the scarcity of labor. The Spanish variety of esparto is still the most valuable, although high prices and careless industrial habits have led to wasteful methods of cropping. Exports have declined from about 6o,000 tons in 1897 to 41,ooo in 1912, but the fluctuations since 19o4 show a fairly steady average; the price runs about 95/- per ton and has fallen from more than double this figure since 1883. T h e Action of Formaldehyde on Wool. A. KANN. (FiirberZeit., xxv, 73.)--When treated with a 4 per cent. solution of for-
maldehyde wool becomes resistant to the action of alkali and loses its affinity for dye-stuffs. By the use of very weak formaldehyde solutions, o.25 or as low as o.I per cent., the wool can be protected against the tendering action of alkali without losing its affinity for dye-stuffs. The reaction between wool and formaldehyde takes place with great ease in slightly alkaline solution and much less advantageously in acid or neutral solution. Wool thus treated can be dyed with sulphide dye-stuffs, it shrinks less on steaming and it can be scoured with caustic alkali, using very little soap. The treated wool reacts with nitrous acid just like untreated wool. This shows that wool does not contain an amino group, for such a group would have been rendered inactive by the formaldehyde. It is concluded that wool contains the imino group and the product of reaction with nitrous acid is a nitrosamine. 'Grand Trunk-Pacific Railway nearing Completion.
ANON.
(Sd. Amer., cix, No. 26, 487.)--This railway, which will give a
new continuous route from the Atlantic to the Pacific, through Canada, has been so far completed that there remains only a gap of 22o miles to be built between Winnipeg and the Pacific Coast. On the mountain section over 6oo miles of track have been completed, and the consulting engineer for the government states that as labor is abundant, the line will in all probability be finished by June I, I914.
CURRENT TOPICS.
7OI
Absorption of Gases by C o a l . - - F . LEPR~NcE-RINGUET. (Comptes Rendus, clviii, 573. ) - - S u c h gases as fire-damp, carbon dioxide, air, oxygen and methane, at pressures ranging from 0.25 to 80 atmospheres, were absorbed by coal to a much less extent than by charcoal, but in both cases the absorption was of the same general character; a state of equilibrium existed for each temperature and pressure, and the absorption markedly decreased as the temperature rose; the increased absorption with increased pressure was rapid at first but gradually tended to a limit. Equilibrium was reached very slowly, and in the case of carbon dioxide especially, evolution of the absorbed gas, however slowly effected, was spasmodic. Results of the ~ame order of magnitude were obtained with coals of widely different composition and size of grain ; they afforded no explanation o f the la'rge evolution of fire-damp observed in very gassy mines. Active Nitrogen. E. TIEDE and E. I)OMC~(E. (Bet., xlvii, 420.) - - B y means of a jointless glass apparatus in which Lindes' commercial nitrogen was passed over copper heated electrically to a temperature measured by a thermo-couple, it was shown that the afterglow was suppressed unless the nitrogen was purposely contaminated with oxygen, provided that the temperature and pressure were such that no dissociation of copper oxide took place. On raising the temperature beyond a limit depending on the pressure, the glow was restored. The phosphorescence of sulphur, iodine, sodium and thallium chloride, observed on heating them in nitrogen which has been subjected to the action of the electric discharge, and attributed by Strutt to the presence of active nitrogen, was similarly suppressed in the absence of oxygen.
The Commercial Importance of Esparto Grass. C.J. KocH. (Tropenpttan~er, xviii, 5 9 . ) - - T h e esparto plant grows best on mixed limestone and gravel soils; its natural region lies between 320 and 4 I° N. latitude, but it is capable of resisting considerable variations in temperature and is found at altitudes up to 30o0 feet. The leaf ranges in length from 3 ° to 7 ° cm., attaining I m. under exceptional circumstances. It is pale green while growing but becomes yellow on drying; it rolls up when drying, attaining its cylindrical form at the ripening stage. About 2oo,o0o tons of the grass are imported ahnost wholly by England ; the quantity has remained stationary for 15 years, a decline from one source being balanced by increased importations from other sources. If the leaf is harvested before maturity the quality of the fibre is very inferior, yielding a semitransparent paper. In most districts the use of the knife is forbidden ; a tuft of grass requires 8 to ~5 ),ears before it becomes productive and may then be " pulled " annually for 3 ° to 50 years. The best time for pulling is the autmnn ; in most countries a close season is fixed by regulation during the earlier months of the year. The
702
CURRENT TOPICS.
[J. F. I.
harvested grass is stored and dried for a considerable time before packing for shipment; the hydraulic pressed bales weigh about 221~ lbs. per cubic foot. The majority of German paper makers are not interested in the grass, partly through unfamiliarity, partly owing to difficulties in procuring freights. Freights from Algiers and Oran run 'about 28/- per ton for Hamburg and 24/- for English ports. The area under esparto in Algeria is about 2,8o0,000 acres, of which three-fourths are in the department of Oran. Regulations as to season of cropping are in force, also certain zones are reserved as a protection against sand-drifts. Exports from Algeria were lOO,788 tons in 1911 and 116,632 tons in 1912, average price 52/- per ton; exports from Tunisia were 5o, I97 tons in 1911, average price67/per ton. Increases from these countries in recent years have taken place at the expense of the Tripoli trade, now practically ruined by war and the scarcity of labor. The Spanish variety of esparto is still the most valuable, although high prices and careless industrial habits have led to wasteful methods of cropping. Exports have declined from about 6o,000 tons in 1897 to 41,ooo in 1912, but the fluctuations since 19o4 show a fairly steady average; the price runs about 95/- per ton and has fallen from more than double this figure since 1883. T h e Action of Formaldehyde on Wool. A. KANN. (FiirberZeit., xxv, 73.)--When treated with a 4 per cent. solution of for-
maldehyde wool becomes resistant to the action of alkali and loses its affinity for dye-stuffs. By the use of very weak formaldehyde solutions, o.25 or as low as o.I per cent., the wool can be protected against the tendering action of alkali without losing its affinity for dye-stuffs. The reaction between wool and formaldehyde takes place with great ease in slightly alkaline solution and much less advantageously in acid or neutral solution. Wool thus treated can be dyed with sulphide dye-stuffs, it shrinks less on steaming and it can be scoured with caustic alkali, using very little soap. The treated wool reacts with nitrous acid just like untreated wool. This shows that wool does not contain an amino group, for such a group would have been rendered inactive by the formaldehyde. It is concluded that wool contains the imino group and the product of reaction with nitrous acid is a nitrosamine. 'Grand Trunk-Pacific Railway nearing Completion.
ANON.
(Sd. Amer., cix, No. 26, 487.)--This railway, which will give a
new continuous route from the Atlantic to the Pacific, through Canada, has been so far completed that there remains only a gap of 22o miles to be built between Winnipeg and the Pacific Coast. On the mountain section over 6oo miles of track have been completed, and the consulting engineer for the government states that as labor is abundant, the line will in all probability be finished by June I, I914.