Page:Popular Science Monthly Volume 41.djvu/733

Rh of oxygen disappear in the liquid condition. Phosphorus or potassium may be plunged into the liquid without any sign of combination. But the magnetic properties of the gas are intensified, and the action of the liquid upon light is identical with that of an equivalent quantity of oxygen in the gaseous condition. But while thus strongly magnetic, liquid oxygen is an extremely bad conductor of electricity. The boiling-point of liquid air is 192° C. below zero, or 10° C. lower than that of oxygen. The doctrine of the text-books that the oxygen liquefies first and the nitrogen afterward is erroneous. Air liquefies as air; but the boiling liquid parts with its nitrogen first, and becomes gradually richer in oxygen. Both in appearance and in spectroscopic behavior liquid air is simply diluted liquid oxygen. The blue tint of the oxygen is lost, and the absorption bands in the red are proportionately faint. Were this globe cooled down to some 200° C. below zero, it would be covered with a sea of liquid air thirty-five feet deep, of which about seven feet would be oxygen.

The Eleventh Census.—In an address delivered before the American Statistical Association Robert P. Porter, Superintendent of the Eleventh Census, stated that sixty thousand persons took part in the work of this census, and that its reports will make not less than twenty-five quarto volumes of one thousand pages each. Of the thirty experts and chiefs of divisions, at least twenty-three held similar or prominent positions in the tenth census. By the use of the electric tabulating machine it has been possible for the first time to aggregate from the schedules all the information which appears in any way desirable. Taking warning from the fate of educational statistics in the tenth census, which largely failed of publication, it was determined to confine the inquiries in the eleventh census to a small number of essential questions most readily answered. The statistics of mortgage indebtedness was a novel feature of this census. Under this head was made only the simple inquiry whether the farm or home was owned or rented, and, if owned, whether free from debt or not. Although these and some other inquiries increased the cost and added to the difficulties of the constitutional enumeration, the superintendent is confident that the work did not thereby suffer to any serious extent. In conclusion, Mr. Porter points out some defects of our census system, and urges a permanent Census Bureau.

The First Cigars in Paris.—Some interesting information has recently been published respecting the time when cigars first came into use. A passage in Hippolyte Auger's Mémoires, now very rare, relates that "our return to Paris (in 1823) was made by way of Orléans. On the road we met quite frequently officers returning from Spain. They swaggeringly had cigars in their mouths—a new habit, which has since become general." Another document carries back the use of the cigar to a somewhat earlier date. The Hermite de la Chaussée d'Antin (vol. iv, 1813), going to call upon his nephew, a young officer on leave in Paris, found him at his hotel in morning costume with a black silk cap on his head, and smoked a Havana cigar with him. The taste for the cigar was so common at that time that grocers, alive to their interests, were accustomed to present them to their customers. A set of complimentary verses, composed by Armand Gouffé for the actor Chapelle, of the Vaudeville, who had added to his professional occupations dealing in colonial produce, included in the nomenclature of articles that might be obtained in his shop—

 Gum, marshmallows, rum and rack. Barley-sugar, almonds, and cigars."

Natural Selection among Egyptians.—"In spite of what appears to us a meager bill of fare, the Egyptian fellah," says Prof. Robert Wallace, "is very often a man of splendid physique, superior in strength and in endurance to the Indian ryot, whom he strongly resembles in many of his ways of working, his habits, his stolid lack of nervousness, and the absence of fear of sudden danger to his person. It is believed that the fellahin are almost exact reproductions of their predecessors for generations, and that, although the country has been frequently conquered, the new-comers were insignificant in numbers to the mass of the people, and consequently became rapidly absorbed. It is also a common belief that the soil and climate, and possibly the Nile