Soils and fertilizers, by Harry Snyder.

Abstract

SOILS AND FERTILIZERS and distilled water. After five years he pulled up the willow and it now weighed 169 pounds and 3 ounces." * He concluded that 164 pounds of roots, bark, leaves, and branches had been produced by the direct transmutation of the water. It is evident from the preceding example that anything like an adequate idea of the growth and composition of plant bodies could not be gained until the composition of air and water was established. The discovery of oxygen by Priestly, in 1774, of the composition of water by Cavendish in 1781, and of the role which carbon dioxide plays in plant and animal life by DeSaussure and others in 1800, form the nucleus of our present knowledge regarding the sources of matter stored up in plants. It was between 1760 and 1800 that alchemy lost its grip, because of advances in knowledge, and the way was opened for the development of modern chemistry. The work of DeSaussure, entitled " Recherches sur la Vegetation," published in 1804, was the first systematic work showing the sources of the compounds stored up in plant bodies. He demonstrated, quantitatively, that the increase in the amount of carbon, hydrogen, and oxygen, when plants were exposed to sunlight, was at the expense of the carbon dioxide of the air, and of the water of the soil. He also maintained that the mineral elements derived from the soil were essential for plant growth, and gave the results of the analyses of many plant ashes. He believed that the nitrogen of the soil was the main source of the nitrogen found in plants. These views have since of investigating the composition and of the study of the character of the different substances from which plants derive their nourishment." 3 Soon after Liebig's first work appeared, the investigations at Rothamsted by Sir J. B. Lawes were undertaken. The most extensive systematic work in both field experiments and laboratory investigations ever conducted have been carried on by Lawes and Gilbert 10 SOILS AND FERTILIZERS weight. But when saturated with water, a cubic foot of peaty soil weighs more than a cubic foot of sandy soil. Clay soils weigh less per cubic foot than sandy soils. The larger the amount of organic matter in a soil the less the weight. Pasture land, for example, weighs less per cubic foot than arable land. Weight is an important property to consider when the total amounts of plant food in two soils are compared. A peaty soil containing i per cent, of nitrogen and weighing 30 pounds per cubic foot has less total nitrogen than a soil containing 0.40 per cent, of nitrogen and weighing 80 pounds per cubic foot. The weight of soils per cubic foot is approximately as follows : 5 Pounds.

Comparative digestibility of wholemeal and white breads and the effect of the degree of fineness of grinding on the former

“…If small, the endogenous contribution of the nitrogen to the faeces is proportionately high. This is well illustrated by some experiments of Snyder (1905) who determined the apparent, digestibility on the same person and under the same conditions of the nitrogen in wholemeal flours ground from Oregon white winter wheat containing 9 % protein and hard winter Weissenberg wheat containing 16-8 % protein. The coefficients were 66 and 78 respectively.…”

“…However, this fact does not explain the whole of the discrepancy between our results and those of previous workers. For example, Snyder (1905) in the experiment quoted on p. 2 using wholemeal and straight run white flours containing 2-94 and 2.68% of nitrogen respectively, obtained a difference in digestibility of 13.6%. In our experiment the bread nitrogen was 90% of the total intake of nitrogen, a considerably greater proportion than in any of the other experiments quoted in Table 1 except those of Rubner, and Martin & Robison.…”

“…Snyder (1901) 83-9 77-6 --88-9 80-4 5. Snyder (1905): (1) 83-9 63-0 ---89-7 76-1 (2) 84-7 77-3 --87 6 79-6 6. Newman et al (1912) - (1901).…”

“…of the degree of fineness of flour on the digestibility of bread for human subjects is very meagre. Table 2 gives values obtained by Snyder (1905) for three breads made from flours of 100, 85 and 70 % extraction and for a bread from a flour of 86 % extraction made by mixing white flour with finely ground bran, which formed 14% of the mixture. Snyder concluded from these experiments that grinding the bran finely increased its digestibility.…”

The Control of Scrub Typhus in Niigata Prefecture 1949. Ii. Treatment of Scrub Typhus in Niigata With Paba and Chloromycetin

“…For example para-aminobenzoic acid (PABA) was found to be of therapeutic value in 1945 (1,2). The more powerful antibiotics, Chloromycetin(3), Aureomycin and terramycin(6) were found one after another against rickettsia.…”