Scientific Notes

For glue to be properly effective, it requirea to penétrate the pores of the wood, and the more a body of gluepenetrates the wood, tke more subgtantial the joint will remain. Larosier, the Freneh Jaw-giver of chemistry, while experimenting on the intensity of different lights, shut himself up in total darknesa for six weeks to increase the sensibility of the eye. The stiff blue clay upon which London is chiefly built contains organic remains whicli indícate the presente, at some former period, of a tropical climate in that locality. ïhe muriatic acid constituting the essential ingrediënt of the gastric juice is conceived to be derived by an act of secretiou f rom conimen salt (muríate of soda) container! in the blood. At the r.ite at which coral reefs are own to increase, - the total age of those surrouiuling Florida is calculated at 135,000, and that of some human remains found in them at 10,000 years. Vhen a chimney tuktts flre f rom a snperabundance of soot, and danger is threatened, throw salt or a wet blanket on the fire below and close it above and belovv to prevent a strong eurrent of air, and it will burn out the soot slowly. The principal vegetable substance8 used in the adulteration of cofCt are chicory, beet-root, carrot, figs, corn, malt, etc. A simple method oí testing coffee fora mixture of chicory is to shake it with water. If pure it remains floating for an hour togethev, whereas chicory sinks. ïhe explorers of the XorthPole have found marine algaj growing at a temperature far below zero, while at a higher temperature the spores cornpletely disappeared. There are, therefore, some vegetables which can only live in intense cold and continuous dryness, and to these the cryptogams of red snow must be allied. The increas-ag applications of electricity have given peculiar interest to the attempts tliat have been made to tore up electric currents for use when lesired. The latest inovatio is due o M. Faure, who has modifled with einarkable success the secondary batte ry of Gaston Plante. The apparitii ■ ".tnsists of two sheets of lead coated i th minium. Dnring the last fouryears 479 color)li.nd persons have been disco vered aiijong 13,855 railway servants in Engni)d. An English scientist notiees the idvantagns of color blindness to engravers and others concerned in the iroJ.uction of illustrations in black and vhite, in consequence of the increased xppreciation of light and slude which s often produced by the defect. One of the best knownimporters of engravngs in New York city is color-blind. For preserving t!ie natural colora of dried llowers and pl.ints, this proces8 has been recoümiended. by Germán cientists: Dissolve one part of saliylic acid in six hundred parts of al-, ohol, heat the solution to boiling in a hallow dish, and draw the plant hrough it slowly; shake off any excess of liquid, dry between blotting paper, ind press in the usual manner. Natural colors are said to be thus preerved in greater perfection than by other processes.