VOL. 4, NO. 7
T HE BEGINNINGS OP LEATHER CHEMISTRY
835
Mineral Tannages Alum tanning dates back to prehistoric times while the chrome process is too recent for mention here. Mmeral tanning was, however, tried a t an early date. Samuel Ashton in 1794 patented a very mixed list of mineral mixtures, including iron, copper, and zinc salts, together with ochre and sulfur. Julius Bordier in 1842 patented "such metallic saline and earthy substances" as combine with hide, rather a broad and indefinite claim. He had, however, the germ of the modern idea of mineral tannage, for he preferred the use of basic sulfate of iron. Such is the story of leather chemistry up to 1850 and further than this we cannot now go.
Science Probes Cause of Living Light. The power of fir&es and certain kinds of insects and lower animals to hecame luminous a t will, is thought by some biologists to be due t o the action of various harmless micro-organisms that live in the animal's body. This theory has recent support from reports of the claim by Dr. Umberto Pierantoni, an Italian scientist of Naples, that ultra-microscopic organisms as well as those visible under the microscope play an important part in such reactions. Dr. Pierantoni believes that the introduction of these ultra-microscopic organisms into the egg of an insect will cause a change in the direction of the development of the embryo leading t o the formation of new organs. Investigations on luminous insects, according to the report t o the scientific journal, Nature, have demonstrated that the presence of such micro-organisms is accompanied by the appearance of highly complicated structures such as lenses, reflectors, refractors, and analyzers of light, due to stimuli exerted by them in the cells in which they become located. If it can be proved that these luminous ultra-microsymbionts, as they are called, actually exist, the baffling phenomenon of bioluminescence would admit of a definite explanation, scientists say.-Science Setvice Scandinavian Coal Mines to Produce Oil. Norway and Sweden are planning t o become independent of the rest of the world so far as their oil supplies are concerned. The coal mined at Kingsbay, Spitzber~en,has been found t o be especially suitable for treatment by the German Bergius process for making d c i a l petroleum and a large plant near the mines is contemplated. A report received by the American Chemical Society also states that Sweden will use coal from the mines a t Braganza Bay for oil production. The hydrogenation of coal by the process invented by Dr. Friedrich Bergius, the German chemist, produces gasoline, lubricating oil, and an artificial anthracite coal from ordinary bituminous coal.-Science Service Studies Downhill Course of Elements in Soils. The decrease in the amount of mineral elements in the sail has been the object of close study by Dr. John S. Burd of the University of California, who spoke before the First International Congress of Soil Science, in session a t Washington recently. He has found that these elements. some of which are essential t o the growth of plants, decrease progressively in concentration as the cropping season advances, and also that in fields continuously under cultivation they show a certain decrease from year t o year. This decrease, he states, is not due entirely to the bodily removal of the minerals by the plants, but that some part of them becomes bound in the soil so firmly that they cannot be pressed out or extracted with water.-Science Service
