Mav, 1905.] 



KNOWLEDGE & SCIENTIFIC NEWS. 



109 



CHEMICAL. 



By C. A. Mitchell, B.A. (Oxon.l, F.I.C, 



ApplicaLtion of the Serum Test to 

 Mximmies. 



Dr. Uhlenhut, of the Hygienic Institute of Greifswald, has 

 attempted to determine the origin of mummy material by 

 means of the specific serum test of which a description was 

 given in " Knowledge & Scientific News " (this vol., 

 p. 86). For this purpose aqueous extracts were made 

 of a large number of mummies ranging from 1000 to 

 3000 years in age. It was found that these were strongly 

 acid and gave a turbidity with normal rabbits' serum, but that 

 when the acidity was neutralised they gave no reaction either 

 with normal serum or with the pracipitiiics that had been 

 rendered specific for human or other serum. This was even- 

 tually shown to be due to the fact that these extracts did not 

 contain any albuminous substances, which if still present ir. 

 the mummies were no longer soluble in water. On the other 

 hand, mummies of comparatively recent date (up to 66 years) 

 yielded extracts that at once showed their origin by giving 

 pronounced precipitates with specific sera. 



* * ■» 



Ancient British Gunpowder. 



In the course of excavations made at the beginning of this 

 year in the public square of St. Martin-de-Ke (Charente 

 Inferieur) the workmen unearthed trenches in which lay 

 skeletons, presumably of those who fell when the town was 

 besieged by the English in 1627. Among the debris was found 

 a spherical iron bomb containing a moist black powder, which 

 had been fired by the besiegers and had failed to explode. 

 The powder, of which a specimen has been examined by M. L. 

 Desvergnes, ignited readily after being dried, and was found to 

 consist of about a third of nitre, a third of carbon, and a fifth 

 of sulphur, the remainder being iron oxide derived from the 

 rusting of the iron shell. After making allowance for this iron 

 oxide and for the fact that a large proportion of the nitre must 

 have been dissolved out by the water, these analytical results 

 are in agreement with the composition of old English military 

 gunpowder, which contained approximately 75 parts of nitre, 

 15 parts of carbon, and 10 parts of sulphur. 



* * * 



The Phosphorescence of Phosphorus. 



Recent experiments made by Herr Jungfieisch show that the 

 phosphorescence of phosphorus is due to the formation of an 

 oxide. Thus if an inert gas such as nitrogen be passed over 

 phosphorus contained in a vessel the vapour issuing into the 

 air is only faintly luminous, but the admission of a minute 

 trace of oxygen with the gas causes the phosphorus to phos- 

 phoresce and enormously increases the luminosity of the 

 vapour. The oxide can be condensed by cold, for phosphorus 

 vapour is rendered non-luminous by being passed through a 

 vessel cooled to 50° F., while an inert gas sulasequently passed 

 through this vessel at a temperature of 60 F. becomes phos- 

 phorescent. 



* * * 



Luminescent Zinc Blende. 



2inc blende which possesses the curious property of 

 luminescence has been discovered in California, Nevada, and 

 other States of North America. The ore has a flaky structure, 

 and varies in colour from light to dark grey. It consists, in 

 the main, of a mixture of white baritejbarium sulphate) and 

 brown sphalerite (zinc blende), and also contains a consider- 

 able amount of gold and about 4 ozs. of silver per ton. It is 

 not radio-active, but when scratched with a knife in the dark 

 emits a series of sparks forming a line of light which follows 

 the point of the blade. 



* * * 



Oxydases and their Work. 



Everyone is familiar with the discoloration that takes place 

 in a cut apple or potato on exposure to the air, and there are 

 many analogous phenomena in the vegetable world. Thus 

 several species of fungi, such as Boletus luridus, turn blue when 

 broken, whilst beetroot rapidly darkens under the same con- 



ditions. In each case such changes are to be attributed to the 

 oxidation of certain constituents within the plant, a combina- 

 tion with the oxygen of the air being brought about through 

 the agency of certain organised ferments or enzymes termed 

 oxydases. An enzyme may be defined as the material sub- 

 stratum of a peculiar form of energy produced by living cells, 

 trom which it is more or less separable. Oxydases, like other 

 enzymes, such as the pepsin of the gastric juice, and the (fms/rtst's 

 of the saliva and of malt which convert starch into sugar, have 

 not yet been isolated in a pure condition. Impure solid pre- 

 parations have been obtained by treating the juice of the plant 

 with alcohol and subjecting the precipitate to further purifica- 

 tion. MM. Chodat and Bach have recently prepared very 

 active and relatively pure oxydases from different fungi, &c., 

 and find that they are not albuminous substances. The 

 activity of oxydases is destroyed by heat, and thus a baked 

 apple or boiled potato can be exposed to the air without 

 darkening in colour. A general test employed to detect oxy- 

 dases is based upon their behaviour with gum guaiacum 

 tincture. Some, the direct oxydases, cause it to turn blue by 

 combination with atmospheric oxygen, while others, terrrjcd 

 indirect oxydases, only give the blue coloration when hydrogen 

 peroxide is also present. This reaction is employed by M. E. 

 Payet as a means of distinguishing between gum arable and 

 gum tragacanth. The former contains an oxydase and gives 

 the blue coloration, while the latter produces no effect upon 

 the guaiacum tincture. Oxydases are also produced by animal 

 cells. Thus they have been detected in milk, in blood, in 

 saliva, in the gills of the oyster and other molluscs and in the 

 internal organs of many animals; and Dr. Dubois attributes 

 the phosphorescence of the glow worm or other animals to the 

 action of an oxydase, to which he gives the poetic name of 

 liicijerase. 



GEOLOGICAL. 



By Edward A. Martin. F.G.S. 



Oscillattions of Shore-Lines. 



Glacialists will feel considerable interest in Dr. Nansen's 

 paper on this subject, which he read before the members of the 

 Research Department of the Royal Geographical Society. 

 Most of his illustrations appear to have been drawn from 

 recent vertical movements of the Norwegian coast. This is, of 

 course, closely bound up with the history of the Glacial Period, 

 and apparently he has no difficulty in subscribing to the views 

 of most modern geologists as to the great downward move- 

 ment which occurred, at the greatest period of glaciation, in 

 northern and north-western Europe, and if this view once 

 be universally accepted we need go no farther for an explana- 

 tion of the arctic-shell-bearing beds, which have been found at 

 1400 feet above the sea, and at lesser heights, at Moel Tryfaen, 

 Gloppa, Macclesfield, and other places. It would be interest- 

 ing to know how he views the suggestion, admittedly to some 

 extent borne out by observations made during the last few 

 years in Spitzbergen, that these shell beds were pushed or 

 floated upward by ice, the molluscs not having themselves 

 actually lived in situ. 



Dr. Nansen stated that 42 per cent, of the continental sur- 

 face of the earth stands between 600 feet above and 600 feet 

 below sea-level, and adduces this fact to maintain that during 

 a long geological period shore-lines have been at very much 

 the same level as now. But though the coast line of Norway 

 had been depressed in places 700 feet below its present level, 

 in Dr. Nansen's opinion, because the land had been pressed 

 down by the weight of the great ice-cap, yet in other places 

 the depression had been very much less, viz., 30 feet to 60 feet. 

 It was remarkable, however, that the laud appeared to have a 

 tendency to a certain mean position of equilibrium ; and that, 

 in spite of this great difference in the amount of depression, 

 the coast had afterwards come to be at almost exactly the 

 same level as that at which it stood previous to depression. 

 On the subject of an actual rising of the surface of the ocean 

 during recent geological times a decision must be postponed 

 for the production of future evidence. An accumulation of 

 ice around the North Pole might so shift the centre of gravity 

 of the earth as to cause a rise of the ocean around our coasts. 

 If, now that the Glacial Period is long past and gone, there 



