3 8 4 



THE POPULAR SCIENCE MONTHLY. 



of adulteration to which the fabric is sub- 

 jected is enormous. Although linen is 

 often used, the favorite adulterator is jute, 

 which is cheaper, is heavy, and so easily 

 takes the dye, and in other ways is made to 

 simulate the silk, that it is the more difficult 

 of detection by an unpracticed eye. If a 

 sample of the " goods suspected to contain 

 other kinds of fibre be treated with hydro- 

 chloric acid of 1.13 specific gravity, the 

 silk will be dissolved, while other kinds of 

 fibres, such as jute and linen, will remain 

 undissolved." 



Opium-poppy in France. The cultiva- 

 tion of the opium-poppy in France is steadi- 

 ly increasing. It now occupies 50,000 acres, 

 of the value of 4,500,000 francs, yielding 

 opium to the value of 2,000,000 francs a 

 year. Different samples of opium, raised 

 in various parts of Europe, ai - e said to have 

 yielded from 8 to 13 per cent, of morphine. 



NOTES. 



The Volcano of Santorin, when last 

 visited, in October, 1871, had ceased giving 

 the small eruptions which had been com- 

 mon almost without intermission since the 

 great eruption of 1866, and the summit of 

 the cr&ter, covered with great blocks of 

 lava, presented the same appearance as in 

 1707. A little steam was still escaping, but 

 this seemed due almost entirely to the va- 

 por of water condensing on the cinders cov- 

 ering the cone. In the north the fumerolles 

 were still active, and all around the stones 

 were covered with sulphur. At the south- 

 east point the volcanic activity had not com- 

 pletely ceased, but had greatly diminished. 

 All this would show that the eruption had 

 entered on its last stage, and after a period 

 of great central activity in 1866-67, accom- 

 panied by a diminution of activity in 1869- 

 '70, it is now again assuming a condition of 

 rest and quietude. Nature. 



Colonel Weitzel, of the Brussels Congress, 

 tells of a village on piles, still inhabited, on 

 the island of Noessa Kimbaugan, off the 

 south coast of Java. Its inhabitants live by 

 fishing. On being asked by Colonel Weitzel 

 why the village was built out into the water, 

 one of the inhabitants said that it was in 

 order to be secure against the attacks of 

 tigers. 



English Sparrows in Australia. Com- 

 plaints are received by the Royal Horticul- 

 tural Society that fruit-crops in Australia 

 have been seriously injured by the English 

 sparrows imported into that country. 



The dolmens, or cromlechs, of Algeria, 

 was the subject of an address by General 

 Faidherbe before the Brussels International 

 Congress. He considers the cromlech to 

 be a monument indicating a place of inter- 

 ment, and thinks it has no other purpose. 

 According to him, the area in which crom- 

 lechs are to be found extends from Pome- 

 rania to Africa. That none exist in Belgium 

 he accounts for by the great density of the 

 population, the cromlechs having been there 

 cleared away. 



We take from the Journal of the Frank- 

 lin Institute the following facts in micro- 

 scopic photography, contributed by L. Erck- 

 mann: Thin sections of plant preparations 

 laid overnight in aniline red solution came 

 out thoroughly colored. When washed in 

 water, the nitrogenous parts retain the red, 

 the non-nitrogenous giving it up. But, if 

 the solution is too concentrated, the image, 

 seen through the microscope, will be red 

 throughout. As the red rays have but little 

 action upon silver iodide, a positive print 

 will show very dark in the nitrogenous, and 

 lighter in the other portions. 



In Great Britain and Ireland there are 

 about 30,000 coal-mines, yielding 120,000,- 

 000 tons per annum. The depths from 

 which this coal is raised vary widely the 

 deepest workings being the Dunkinfield and 

 the Rosebridge collieries, near Wigan. The 

 depth of the latter is 2,418 feet, and the 

 average temperature 95 Fahr. 



We have in the Gardener's Chronicle 

 a remarkable instance of the luminosity of 

 fungi. The spawn of some unknown spe- 

 cies of fungus, growing on a trunk of spruce 

 or larch, was found to give a perfect blaze 

 of white light along the track where the 

 trunk had been dragged. The light was 

 enough to read the face of a watch, and it 

 continued for three days. 



Attention has lately been directed to a 

 new method for printing on cloth, the inven- 

 tion of Mr. E. Vial. The fabric to be printed 

 is first impregnated with a solution of nitrate 

 of silver, or other metallic salt, which, when 

 brought in contact with zinc or copper, will 

 be reduced to the metallic state. The pat- 

 terns are designed on zinc or copper, and, 

 wherever contact is made between the metal 

 plate and the cloth, a metallic precipitate is 

 firmly fixed upon the tissue. If nitrate of 

 silver is used, the color of the precipitate, 

 and therefore of the cloth, may be varied by 

 varying the strength of the solution, from a 

 brilliant gray to a deep black. The color 

 withstands acids, alkalies, or soaps. 



The sewage of Tunstall, in Staffordshire, 

 England, is to be converted into cement by 

 precipitation, by the process of Major-Gen- 

 eral Scott. This system is already in opera- 

 tion in Birmingham, West Ham, and Ealing. 



