FRAGMENTS OF SCIENCE. 



283 



ence. The true scientific spirit prompts 

 to thorough inquiry; it will have noth- 

 ing to do with hasty generalizations 

 that may glitter but do not convince; 

 it puts a restraining hand on all imma- 

 ture conclusions, and demands, above 

 all else, careful, thorough observation. 

 It shuns all shams. Good, honest work 

 is the only passport to the domain of 

 science. 



Constitution of the Funafuti 

 Atoll. — In the boring of the coral atoll 

 of Funafuti, Professor David, of the 

 University of Sydney, reached a depth 

 of 697 feet, and a subsequent boring was 

 made down to about 1,000 feet. The core 

 obtained by the David party was sent to 

 England and placed in the hands of 

 Professor Judd for investigation. The 

 general statement is made respecting it 

 that the material brought up presents 

 much the same character throughout, 

 and so far is regarded as supporting 

 Darwin's theory. There are no layers 

 of chalky ooze, such as Murray's hy- 

 pothesis might have made possible, and 

 no trace of volcanic material has been 

 found. The later boring beyond 700 

 feet passed through a hard limestone 

 containing many well-preserved corals. 

 In a boring of the bed of the lagoon 

 down to 144 feet, after passing through 

 101 feet of water, the first 80 feet below 

 were found to consist of the calcareous 

 alga Halimeda mixed with shells, and 

 the remaining 64 feet of the same mate- 

 rial mixed with gravel. 



Metallic Calcium. — Metallic cal- 

 cium, as prepared by Professor Moissan 

 from solution in liquid sodium, sepa- 

 rates in hexagonal crystals which have 

 a specific gravity of 1.85 and melt at 

 760° ill vacuo. On solidifying, the metal 

 is somewhat brittle, is less malleable 

 than potassium and sodium, and shows 

 a crystalline fracture. When free from 

 nitride it is silver-white in color, and 

 has a brilliant surface. Heated to red- 

 ness in a current of hydrogen, a crystal- 

 line hydride, CaHo, is formed. When 

 pure, calcium is not acted upon at ordi- 

 nary temperatures by chlorine, though 

 at 100° C. the action is decided. But 

 if the metal contains nitride, chlorine 

 attacks it at the ordinary temperature. 

 At 300° C. calcium ignites and burns 

 brilliantly in oxygen. Gently warmed 



in air, it burns with brilliant scintilla- 

 tions. It combines with sulphur, with 

 incandescence, at 400° C. At a red heat 

 it unites actively with lampblack, giv- 

 ing a carbide, CaC.. It gives some brit- 

 tle alloys with magnesium, zinc, and 

 nickel. The alloy with tin slowly de- 

 composes water. A crystalline amal- 

 gam is formed with mercury, which 

 may be distilled in hydrogen at 400° 

 C, but which forms nitride when heated 

 in nitrogen. Heated to redness with 

 potassium or sodium chloride, calcium 

 sets the metal free. Water acts on cal- 

 cium only very slowh', with the evolu- 

 tion of hydrogen. In liquefied ammo- 

 nia at —40° C. calcium ammonia is 

 formed — a reddish-brown solid. 



Prosperity and Enterprise in 

 Mexico. — The increasing prosperity of 

 Mexico is one of the striking features 

 of current history. In four years the 

 imports of the country increased from 

 $30,000,000 in 1894 to upward of $45,- 

 000,000 in 1898, the 'average for five 

 years having been $40,000,000. The 

 chief sellers to IMexicans are the United 

 States, Great Britain, France, and Ger- 

 many, and the keenness of the compe- 

 tition for trade is shown in the fluctu- 

 ations in the relative shares of it of the 

 several countries. Spain has a small 

 share of trade, which is growing. In- 

 dustrial enterprises are being developed 

 throughout the country with energy, 

 enterprise, and success. Cotton and 

 linen factories have been established, 

 attention is given to the erection of 

 woolen mills, and a noticeable activity 

 prevails in mining industries. Under 

 all these influences the railroads are 

 prosjjering too. 



A Question of Economy. — A paper, 

 " Shall we grow the Sugar that we con- 

 sume? " by Freeman Stewart, called out 

 by an article by ex-Secretary Wilson, 

 besides matter bearing directly on the 

 question, embodies observations on gen- 

 eral political principles. Thus, it seems 

 necessary to observe " that the idea that 

 republicanism requires our public offi- 

 cials to act as mere weathercocks for 

 the transient waves of popular clamor 

 and excitement is also a deplorable de- 

 lusion, Avhich, if persistently carried into 

 eff"ect, will soon utterly destroy republi- 

 canism. As free institutions depend on 



