SCIENTIFIC MISCELLANY. 187 



mountain chains. In general it will be modified in its properties by causes 

 acting after its formation, such as partial distillation, etc. Petroleum de- 

 posits will always be accompanied by salt water or rock salt. Often and 

 especially where the deposit is among hard and compact rocks, it will be 

 accompanied by gas, such as hydrogen, sulphuretted hj^drogen, carbonic 

 acid, etc. — JRevue Industrielle. 



Chemical Prizes. — Among the prizes offered by the German Verein zur 

 Beforderung des Gewerbfleisses, the following may prove of interest to our 

 readers: 



A silver medal, or its value, and 900 marks (about $200) for an opaque 

 red enamel for gold, silver, copper and bronze. 



A gold medal, or its value, and 3,000 marks, for a substitute for 

 caoutchouc, the same for a suitable substitute for gutta percha. 



A prize of 1,000 marks for a concise, critical and practical treatise on 

 cements; also 1,500 marks for the best investigation of the cause of a 

 change in the zero point of thermometers, with a method of preventing or 

 remedying it. 



A prize of 2,000 marks for the best series of iron and manganese alloys; 

 at least twenty samples to be prepared, containing from 0.5 to 5 per. cent. 

 of manganese. 



To Distinguish Between Cotton and Wool in Fabrics. — Eavel out the 

 suspected cotton fibre from the wool and apply flame. The cotton will burn 

 with a flash, the wool will curl up, carbonize, and emit a burned, disagree- 

 able smell. Even to the naked eye the cotton is noticeably different from 

 the filaments of wool, and under the magnifier this difference comes out 

 strongly. The cotton is a flattened, more or less twisted, band, having a 

 verj^ striking resemblance to hair, which, in reality, it is ; since, in the con- 

 dition of elongated cells, it lines the inner surface of the pod. The wool 

 may be recognized at once by the zig-zag traverse marks on the fibres. The 

 surface of wool is covered with these furrowed and twisted fine cross lines, 

 of which there are 2,000 to 4,000 in an inch. On this structure depends its 

 felting property. Finally, a simple and very striking chemical test may 

 be applied. The mixed goods are unravelled, a little of cotton fibre put into 

 one dish and the wool in another, and a drop of strong nitric acid added. 

 The cotton will be little or not at all affected; the wool, on the contrary^ 

 will be changed to a bright yellow. The color is due to the development 

 of a picrate. — Warehouseman. 



The Gardener's Chronicle announces a new material for paper in a well 

 known American grass, Zizania aquatica. It is stated that the Zizania yields- 

 fully as much of the raw material as esparto, and has the great and peculiar 

 merit of being comparitively free from silicates. Paper made from it is- 



