Water Nitrogenous substances Nitrogen-free extractives Ash Nitrogenous substances Fat Ash Nitrogen 71.13 63-14 76-28 72-03 70-96 78-82 21-76 18.92 21.93 20.96 19-86 19.86 6.25 17.14 1.02 5.41 7.70 0.82 0.46 0.41 0.86 0-80 0-77 1.14 1.07 0.50 3-48 3:03 3.51 Calculated to Dry Substance. 75-37 51-33 92.48 74-93 68-38 93-76 8.22 14-79 12.00 11-13 15-01 II. MEAT-EXTRACTS. The following are the analyses of the principal meat-extracts manufactured in the colony, together with the analyses of Australian and South American extracts : 21-79 17-16 13-10 24-21 13-46 17-28 20-65 16-42 19-04 19.48 4.61 5.38 8.21 7.45 10.92 3-38 5.22 6.92 3.23 50 per cent. alcohol, but soluble in water Substance insoluble in 15-16 20-92 16-82 15-08 22.48 18-58 80 per cent. alcohol, but soluble in water and 50 per cent. alcohol 1.64 1.39 0-32 0.48 0.62 0.58 0.71 0.29 0.42 0.46 0.28 1-22 1.96 1.39 1-06 1.15 0.97 Substance soluble in 8057-42 56-54 61-87 52-90 53-14 60-55 The meat-extracts numbered 1 to 6 are from various factories in the colony. The substance insoluble in water in Nos. 1 and 4 was meat-fibre, while that in No. 6 was phosphate of lime. No. 7 was made from sheep-heads, and was sold as stock." The high fat-content was mainly brain-fat, and, as this fat readily emulsifies with water, it could not be readily removed from the liquor; this article is not now manufactured in this colony. No. 8 was taken from a trial lot of rabbit-extract, and, while this article is not manufactured in New Zealand, its analysis indicates the possibility of utilising this material. For permission to publish these results I have to express my thanks to the general manager of the Christchurch Meat Company (Limited), in whose laboratory most of the work was carried out. ART. XXIX.-The Fixation of Atmospheric Nitrogen by Nitrogenfixing Bacteria in Certain Solutions. By A. M. WRIGHT, F.C.S. (Berlin), M.Am.C.S. [Read before the Philosophical Institute of Canterbury, 11th December, 1907.] THIS paper is the record of the work carried out preliminary to soil experiments to determine under what conditions of alkalinity and acidity nitrogen-fixing bacteria will fix atmospheric nitrogen. A solution of 1 gram each of cane-sugar, ammonium-sulphate, magnesium-sulphate, and potassium-sulphate in 1 litre of water was prepared to 10 cubic centimeters of this solution 100 milligrams of cotton-wool containing the bacteria were added. This was then rendered acid or alkaline. The degrees of acidity or alkalinity are expressed as parts of calcium-oxide per million, this being the usual method of expressing these results in soildeterminations. The experiments were carried out in Kjeldahl digestion flasks. At the end of the experiment it was merely necessary to add mercury and sulphuric acid, and proceed with the nitrogen determination as in other Kjeldahl estimations.* * Bull. No. 81, Bureau of Chemistry, U.S.A. Dept. of Agric., p. 152. Experiment 1. Acidity required, 254 parts of CaO per million to neutralise solution. Experiment 2. Acidity required, 646 parts of CaO per million to neutralise solution. Experiment 3. Acidity required, 1,050 parts of CaO per million to neutralise solution. Experiment 1. Alkalinity equals 254 parts of CaO per million. It will be seen from the above that the bacteria fix nitrogen in the greatest quantity when the media are neutral or slightly alkaline. In slightly acid media the nitrogen is fixed in less. quantities, while when the acidity is 1,050 parts per million the fixation is relatively small. The fixation also decreases as the alkalinity increases over 254 parts per million. For permission to publish these results I have to express my thanks to the general manager of the Christchurch Meat Company (Limited), in whose laboratory much of the work in connection with this paper was carried out. ART. XXX.-The Transformation of Barley into Malt. [Read before the Wellington Philosophical Society, 1st November, 1905.] THE practice of malting and brewing has been known from very ancient times. Herodotus describes (Herodotus, Book II, cap. 77) beer prepared from barley as the ordinary drink of the Egyptians in his day (430 B.C.), and, in common with other writers of antiquity, he ascribes the art of brewing to Isis, wife of Osiris, better known as Rameses II (1960 B.C.). It is therefore a matter of surprise that, although the process of malting has been carried on for close on four thousand years, so little is really known about it except by persons connected with that industry. In the present paper I intend giving a short description of the barley-corn, an explanation of the chemical changes that take place within the barley-corn during germination, and an account of the method by which these changes are brought about in practice. The first subject to receive attention is the structure of the barley-corn. You will notice that the grain is spindle-shaped, and about in. in length, one end being sharper than the other: this was the end that was attached to the ear of barley previous to threshing. Again you will notice that the grain is enveloped by a very strong skin or husk-paleæ consisting of the inner and outer palea. Beneath the paleæ are two coats or skins, the first known as the "pericarp," and the second, which is really the true covering of the seed, is known as the "testa.” A narrow furrow runs down the more convex side of the grain; this side is known as the "ventral" side, while the other, which is comparatively flat and smooth, is termed the "dorsal" side. If we now bisect a grain of barley longitudinally-that is, through the ventral furrow-we shall find that the grain con6 DIAGRAM OF A LONGITUDINAL SECTION OF A BARLEY-CORN. A, endosperm; B, germ. a, starch-containing cells of the endosperm; b, aleurone layer; c, absorptive epithelium of the scutellum; d, plumule; e, rootlets; f, scutellum. sists of two principal parts-(1) the germ or embryo (the part endowed with actual life); (2) the endosperm, the starchy portion of the grain. The germ, which in the dried barley-corn forms only about one-thirtieth of the whole, is separated from the endosperm by a barrier known as the "scutellum." This scutellum consists of layers of compressed empty cells; and on the side which is pressed on the endosperm is situated a layer of elongated cells, known as the "absorptive epithelial layer." These cells have most important functions, and play an important part in the feeding of the young embryo when it commences to develop into a young plant. The germ consists of two distinct parts-plumule and rootlets. During germination this plumule becomes the acrospire of the malt, and if the seed were sown in the ground and germination pushed on to com pletion the acrospire would develop into the actual stem of the plant, and, under similar conditions, the rootlets would form the roots. |