6o 



NATURE 



\Nov, 15, 1888 



The zinc, manganese, and cobalt salts of molybdic acid, 

 H2M0O4, have been obtained pure and in fine crystals by M. 

 Coloriano, of Bucharest. Although molybdenum is so interest- 

 ing an element, forming as it does such a beautifully graduated 

 series of oxides and their corresponding salts, it is ratherremark- 

 able that so little is yet known concerning the most important of 

 these latter, the molybdates. On attempting to obtain the zinc, 

 manganese, and cobalt molybdates by double decomposition, 

 using solutions of known strength of the nitrates of the metals in 

 question, and of ammonium molybdate, amorphous precipitates 

 were thrown down, consisting of hydrated acid salts of molybdic 

 acid. On digesting these precipitates for a short time with water, 

 it was found that they became rapidly converted into a mass of 

 crystals, which were eventually separated from the remaining 

 amorphous substances, washed and dried. They were then sub- 

 jected to analysis, and were found to be normal molybdates, con- 

 taining water of hydration so firmly combined that the first 

 traces only commence to be expelled at 150° C. and perfect 

 dehydration cannot be effected lower than the temperature of 

 boiling sulphur (447°). Hence it is concluded that the water 

 present is of "constitution." The crystals of zinc molybdate, 



/OH 

 ZnMo04 • HjO or MoOj (^ , are transparent and 



^O— Zn— OH 

 colourless, forming acicular stellar groups. They dissolve but 

 sparingly in water, readily, however, in dilute acids. The man- 

 ganese salt, MnMo04 • H2O, is probably isomorphous with the 

 zinc molybdate just described, the crystals being very similar in 

 form, but distinguished by possessing a bright yellow colour. 

 The cobalt compound, C0M0O4 . H^O, is also similar in consti- 

 tution, but the crystals are very much more beautiful. They 

 exhibit a magnificent violet colour, and are almost insoluble in 

 pure water, though readily dissolved by even very dilute acids. 

 All three salts iare probably isomorphous, and are similarly at- 

 tacked by alkalies. An analogous nickel salt was also obtained, 

 the crystals being of precisely the same habit as the three salts 

 above described ; but owing to the extreme slowness with which 

 the amorphous acid salt is converted into the crystalline normal 

 one, sufficient quantities have not yet been obtained pure for 

 analysis. From the description given, however, by M. Coloriano, 

 it maybe accepted that zinc, manganese, cobalt, and nickel form 

 isomorphous normal molybdates each containing one molecule of 

 water of hydration. 



An interesting paper on "the nephrite question," by Dr. A. 

 B. Meyer, is printed in the American Anthropologist. Dr. 

 Meyer is of opinion that too much has been made of the fact 

 that objects of nephrite and jade have been found in districts 

 where these minerals in their natural state have not yet been 

 discovered. It is rash, he thinks, to conclude that the ob- 

 jects must have been brought from a great distance. Pre- 

 historic men may, he suggests, have found nephrite and jade 

 in places where they have escaped our notice. "It may be 

 that the people of prehistoric times continually sought the 

 valuable material in a way quite different from the one we 

 adopt. That boulders in the rivers formed their main source of 

 supply is proved by the fact that a large number of the hatchets 

 show the boulder characteristics, and they certainly left 'no stone 

 unturned in their endeavour to find them, while we never think 

 of looking for them in rivers. They may also have searched for 

 still greater finds, the last view being supported by the fact that 

 finds have been made as late as the last century in North 

 Germany, in the sand near Potsdam, at Schwensal, near Merse- 

 berg, and at Leipzig, and these were evidently nephrite boulder-; 

 01 the North German diluviums. The remarkable block at 

 Leipzig weighicd over 38 kilogrammes ; it is looked upon by Prof. 

 Fischer and others as having been accidentally lost at that 

 place, and they think that the raw material is of Asiatic origin. | 



Considering that the block weighed nearly 100 pounds, this i» 

 not very likely, and I am of the opinion that this nephrite 

 boulder came from Scandinavia, and that it was transported 

 by ice." 



Lieut. D. Bruun, of the Danish army, having had a moss 

 dug out in Finderup, in Jutland, has made some interesting dis- 

 coveries. In the moss were found trunks of oak, beech, and fir 

 trees, from 6 to 30 inches in diameter. The branches had in some 

 cases been cut off, but the bark remained. By the side of one 

 of the oak trunks two earthen vessels were discovered, and near 

 another a third, shaped like an urn. In the latter lay a sandal 

 cut from a piece of leather, with flaps, and leather straps for 

 tying to the ankle, the length of the sandal being 7 inches. It 

 seemed as if the trunks of trees had been placed in a certain 

 position for some purpose or another. About 20 feet further to 

 the south, and at the same depth, viz. 6 feet, a yoke of oak was 

 found, 5g feet long and 3 inches thick, being fairly cylindrically 

 cut out in the centre. At each end were holes, in one of which 

 remained a strap of leather. Other implements of oak were also 

 found, evidently used for carrying. Some of them seemed part 

 of a wheel, Clo?e to the yoke another earthen urn was dis- 

 covered, which, like the three referred to, was surrounded with 

 sprigs of heather and bramble. Formerly some horns of 

 bullocks and the skeleton of a man in a fur coating were 

 found in the moss. The various objects are now in the 

 Copenhagen Museum, and are said to date from the early Iron 

 Age. 



During the past summer a great "kitchen-midden" at 

 Grenaa, in Jutland, was the subject of research by the authori- 

 ties of the Norse Museum at Copenhagen. It is situated a couple 

 of miles from the sea in the midst of a wood. The layers in 

 the midden were clearly defined, the numerous places of cooking 

 being made conspicuous by ashes and remains of charcoal, 

 together with fragments of coarse pottery. A large quantity of 

 animal remains were found, viz. knuckles and bones, which had 

 been split in twain or crushed and the marrow extracted. There 

 were also many shells of oysters and other mollusks. The bones 

 were those of deer, boar, seal, fox, wolf, dog, swan, and goose, 

 with some of fish. Many flint weapons and implements were 

 found, as well as some of horn and bone. Several of the latter 

 had traces of ornamentation. 



We have received the Report of the Survey of India for the 

 year ending September 30, 1887. During the year, the trigono- 

 metrical party has extended the triangulation on the Madras 

 coast 170 miles, this being part of the general scheme to com- 

 plete the triangulation on the coasts of India and Burmah. The 

 aggregate results of the topographical surveys amounted ta 

 17,510 square miles, and the areas of forests to 34,289 miles. 

 In Basti, close upon 2,000,000 plots were cadastrally surveyed, 

 the extent of each only averaging 0-27 of an acre ; in Gorakhpur, 

 in a considerably larger area, less than i,ooo,coo plots were sur- 

 veyed. After a little preliminary difficulty, it was found possible 

 to advantageously employ village natives in this work. Altoge- 

 ther, 4273 square miles were cadastrally surveyed. A new map 

 of Calcutta, on a scale of 50 feet to an inch, has also been 

 undertaken. The longitude determinations have been sus- 

 pended, but the latitudes of five stations on the meridian of 80"' 

 have been completed. Advantage has been taken of the various 

 military operations in Upper Burmah to record additional geogra- 

 phical information. The total number of maps issued amounted 

 to 178,398. At Dchra Dun, photographs of the sun were taken 

 for the Solar Physics Committee, South Kensington, on every 

 available day — in all, sixty-three days being lost. Attempts 

 were also made to photograph the corona by means of stained 

 plates, but their success seems somewhat doubtful. As usual, 

 the Report is accompanied by maps showing the extent of the 

 various operations. 



