February, 1913. 



KNOWLEDGE. 



61 



methyl alcohol and furfural could be obtained as by-products 

 from the residue. A yield of thirty to thirty-five gallons of 

 proof spirit would be obtainable from each ton of sawdust, 

 and on this basis it is calculated that in a factory where two 

 hundred tons a week were treated, the yearly output of spirit 

 would be from three hundred thousand to four hundred 

 thousand gallons. Unfortunately for the development of 

 this side of the scheme, the restrictions of the Spirit Act of 

 1880 bar the way, and fresh legislation is required before 

 anything can be done in this direction. 



FABRICS OPAQUE TO X-RAYS.— It has long been 

 known that silk can be loaded with various metallic salts, and 

 advantage is taken of the fact in commerce to sell silk which 

 is sometimes weighted with as much as one hundred and fifty 

 per cent, of a tin salt. A more legitimate use of this absorptive 

 power of silk is described in the Comptes Rendus (1912, 

 CLV, 706) by M. L. Droit, who has found that by using 

 certain lead salts for the weighting, a silk fabric may be 

 rendered opaque to the passage of X-Rays. For example, a 

 material thus prepared by treatment of the silk with lead 

 phosphotannate and other salts contained sixty-eight percent, 

 of mineral matter, including thirty-four per cent, of lead oxide, 

 twenty-four per cent, of tin oxide, eight per cent, of phosphoric 

 anhydride, and two per cent, of lime and alkalies. Slight 

 discharges, of X-Rays were practically arrested by two layers 

 of this fabric, while six layers were found a sufficient protection 

 to the skin against the action of an ordinary discharge of 

 medium strength. This fabric had the same protective effect 

 as a sheet of copper 0-044 millimetres in thickness, and had 

 the great advantage of flexibility, even when used in a thickness 

 of several layers. 



THE ODOUR OF CLAYS.— An investigation of the 

 cause of the well-known characteristic odour of certain clays 

 has been made by Dr. P. Rohland (Zeit. physiol. Chem., 

 1912, LXXXI, 200). The peculiar odour which may be 

 imparted to other substances either of a colloidal or crystal- 

 loidal character, is rendered more perceptible by moistening 

 the clay with water or alkali solution, especially in the case of 

 kaolin clay. It is suggested that in the formation of such 

 clays during the weathering of granitic rocks, bacteria or 

 other micro-organisms may have had a share in the disinte- 

 gration and that the odour may be due to the presence of their 

 dead cells. In support of this view it is pointed out, that 

 organic matter is frequently present in kaolin clay, and plays 

 a part in rendering it plastic. If the clay has been purified 

 by sedimentation in water so that the organic colloidal sub- 

 stances have been removed, it ceases to be plastic. Kaolins 

 rich in such organic matter are not only very plastic, but also 

 possess the property of taking up other colloids to form loose 

 absorption compounds. When kaolin clay is digested with a 

 mixture of water and an aromatic hydrocarbon, such as 

 benzene, it becomes quite impervious to the hydrocarbon, 

 though it will still allow the water to pass. 



COMPOSITION OF THORIANITE.— An examination of 

 various specimens of the mineral thorianite has been made 

 by Mr. M. Kobayashi (Science Reports, Tohoku University, 

 Japan, 1912, I, 201), who concludes that there are two 

 varieties, one of which contains about seventy-eight per cent 

 of thorium oxide, and about fifteen per cent, of uranium oxide, 

 while the other contains about sixty per cent, of thorium oxide 

 and thirty-three per cent, of uranium oxide. In the first of 

 these varieties the rates of ThO- 2 to UO2 would thus be as 

 6:1, while in the second the ratio would be as 2 : 1. The 

 remarkable discrepancies in analyses, previously published, of 

 the composition of this mineral are readily explained on the 

 assumption that the materials examined consisted of mixtures 

 in vaiying proportions of the two varieties. 



Some years ago a specimen of thorianite from Ceylon was 

 described by Messrs. Dunstan and Jones (Proc. Roy. Soc, 

 1906, LXXVII A, 546). This was very rich in uranium, and 

 the proportion between the two oxides was taken to indicate 

 that the uranium and thorium oxides were present in 



thorianite as isomorphous mixtures and were not in chemical 

 combination. Mr. Kobayashi is opposed to this view on the 

 grounds that the molecular ratios mentioned above could 

 scarcely be accidental, and that while ignited thorium oxide is 

 nearly insoluble in nitric acid, thorianite is fairly soluble even 

 after ignition. 



GEOLOGY. 



By G. W. Tyrrell, A.R.C.Sc, F.G.S. 



THE SUSSEX SKULL. — A most important discovery of 

 human fossil remains has been made by Mr. Charles Dawson 

 in a gravel-pit near Piltdown Common, Fletching, Sussex, and 

 described at a recent meeting of the Geological Society. The 

 section, about four feet thick, consists mainly of water-worn 

 fragments of Wealden ironstone and sandstone, with occasional 

 chert pebbles, and a considerable proportion of water-worn 

 flints. In addition to a portion of a human skull which was 

 found by workmen, Mr. Dawson obtained half a human man.- 

 dible, broken pieces of the molar of a Pliocene type of 

 elephant, a rolled cusp of a molar of Mastodon, and teeth of 

 Hippopotamus, Castor, and Eqnus, with a fragment of an 

 antler of Cervus elaphus. All these fossils, including the 

 human, were well mineralised with oxide of iron. Many of 

 the iron-stained flints resemble the "eoliths" from near 

 Ightham, and with them were obtained a few Palaeolithic 

 implements of Chellean type. 



The Piltdown gravel is eighty feet above the river Ouse, 

 and less than a mile to the north of the existing stream. The 

 authors believe that the gravel is of the same age as the 

 contained Chellean implements. The various teeth are 

 believed to have been derived from older gravels ; but the 

 human skull and mandible, which do not show signs of water- 

 transportation, are assigned to the period of the deposition of 

 the gravel. The remoteness of this period is indicated by the 

 fact that the Ouse has since deepened its valley by eighty feet. 



The human remains were described by Dr. A. S. Wood- 

 ward, who suggests that they belonged to a female individual, 

 and represent a hitherto unknown genus and species. In an 

 appendix, Professor Elliot Smith remarks that although the 

 brain shows a general similarity to the cranial casts of 

 Palaeolithic man, especially those of Gibraltar and La Quina, 

 it is smaller and more primitive in form than any of these. A 

 most noteworthy feature is a pronounced gorilla-like drooping 

 of the temporal region, indicating feeble development of that 

 part of the brain which is known to be related to the power of 

 speech. Dr. Woodward concluded that the jaw was simian in 

 type, although found in association with a human type of 

 skull, and in this he was supported by Professor Elliot Smith 

 and Sir E. Ray Lankester. In the discussion Professor 

 Keith thought that the simian character of the jaw and the 

 primitive characters of the skull were incompatible with 

 Chellean age. In his opinion the skull was of the same age 

 as the mammalian remains which were admittedly Pliocene. 

 Hence he believed that Tertiary man had been discovered in 

 Sussex. Mr. Clement Reid was of the opinion that the 

 Piltdown deposit, and the plateau on which it rests, belong to 

 a base-level plain which originated about the period of 

 the Brighton raised beach. The deposit was not Pre-Glacial 

 or even early Pleistocene, but occurred at the very base of the 

 great implement-bearing succession of Palaeolithic deposits in 

 the south-east of England, and belonged to an epoch long 

 after the first cold period had passed away. 



THE MOINE GNEISS.— The new geological Survey 

 Memoir bearing the cumbrous title, " The Geology of Ben 

 Wyvis, Cam Chuinneag, Inchbae, and the Surrounding 

 Country," is a most interesting production, and students of 

 the petrology of the metamorphic rocks will find in it an 

 excellent discussion, by Dr. J. S. Flett, of the Moine and 

 other gneisses and schists in this area. The Memoir describes 

 an area of four hundred and thirty-two square miles, almost 

 all of which lies in Ross-shire and extends westward from 

 the Cromarty and Dornoch Firths. A few small inliers of 

 Lewisian gneiss occur in the south-west, but the major part 



