444 



brittle and worthless. Julius Jacobi (in Bayerischers Industrie und Oe- 

 ioerheblattj proposes ^ method of freeing iron ores from phosphorus, 

 and at the same time saving the phosphoric products and economizing 

 them for agricultural purposes. His process consists in roasting the 

 ore and crushing it, and, after placing it in a proper receiver, submitting 

 it to the action of water charged with sulphurous acid under pressure. 

 The ore is then washed with water to remove all the soluble products, 

 and the phosphoric acid precipitated from the water with fresh burnt 

 lime, and the phosphoric acid obtained as a neutral phosphate of lime. 

 If the process is eflectual, and not too expensive, the proposed method 

 is very important, as rendering many ores available which are now re- 

 garded as worthless, and at the same time supplying a demand in agri- 

 culture which has heretofore been %ut imperfectly met. If the sulphur- 

 ous acid can be furnished from the ores themselves, in the process of 

 roasting, it will go far in reduciug the expense. 



The Osage orange. — The Madura aurantica has become a familiar shrub 

 in most parts of the United States, from its general use as a hedge-plant; 

 but it is now proposed to utilize the Osage orange for other purposes. A 

 decoction of the wood is said to yield a beautiful and very i)ermanent 

 yellow' dje, and this decoction, carefully evaporated, forms a bright 

 yellow extiact called aurantine, which may be used in imj)arting its 

 color to fabrics. In addition to this coloring-matter, the wood of the 

 Osage orange is rich in tannin. Experiments made in Texas represent 

 that hides are tanned quicker with the wood of this tree than with oak 

 bark. The seeds yield a bland, limpid oil, resembling olive-oil, and 

 which may, in general use, be substituted for it. 



Ejject of atmosplieric pressure. — Mr. Paul Best, (Les Mondes, July 11,) 

 in a A^ery interesting memoir, shows that the destruction of life by di- 

 minished barometric pressure is chiefly to be attributed to deficiency of 

 oxygen. An animal that will die with the pressure reduced to 18 cen- 

 timeters (7 inches) of mercury, will endure a reduction to 6 centimeters 

 (2.4 inches) if an additional supply of oxygen be furnished. And the 

 converse is also true, that the danger of too great pressure is from the 

 increased amount of oxygen in a given volume of air inhaled. 



Topographical measurements in the West. — Professor C. Thomas, assist- 

 ant of Dr. Hayden, United States geologist, has compiled and published 

 a series of tables giving imj)ortant data with regard to the Eocky 

 Mountain regions and the great plateau of the West. The southern 

 portion of the great American i^lain, the Llano Estacado, has an aver- 

 age elevation^of about 4,000 feet above the sea. The ascent from Pres- 

 ton to the margin of the Staked Plains is about 10 feet to the mile, and 

 from Fort Smith to the northern margin of the plains the ascent is G 

 feet to the mile. From Kansas City to Denver Junction the ascending 

 grade is a little more than 8 feet to the mile. From Omaha to Cheyenne 

 the grade ascends just 10 feet per mile. The ascent from Fort Union at 

 the mouth of the Yellowstone to Fort Benton is only about 2} feet per 

 mile, while from that point west to the base of the mountains, the aver- 

 age ascent reaches 20 feet to the'mile. The plateau which lies between 

 the Black Hills and the Wahsatch range of mountains* has an 

 elevation of about 6,500 feet above the sea, 1,200 feet above the western 

 border of the plains, and 2,200 feet above the Salt Lake basin. 



The Rio Grande, from Isleta to El Paso, has a fall of about 5 feet to 

 the mile, but from Isleta south for some distance its descent is 6 feet per 

 mile. The Canadian, from the mouth of Pajarito Creek, for two hundred 



