174 



BECEEATIVE SCIENCE. 



will curl up from tke hot wick ; now if a 

 flame be applied to this smoke, even at a 

 distance of two or three inches from the 

 candle, the flame will run down the smoke 

 and rekindle the wick in a very fantastic 

 fashion. To perform this experiment nicely 

 there must be no draught or " banging" doors 

 while the mystic spell is rising. 



THE MAGIC EGG. 



Take a pint of water, and dissolve in it as 

 much common salt as it will take up ; with 

 this brine half fill a tall glass, then fill up 

 the remaining space with plain water, pouring 

 it in very carefully down the side of the 

 glass, or into a spoon, to break its fall. The 

 pure water will then float upon the brine, and 

 in appearance the two liquors will seem but 

 as one. Now take another glass, and fiU it 

 with common water. If an egg be put into 

 this, it will instantly sink to the bottom ; but 

 if, on the contrary, the egg is put into the 

 glass containing the brine, it will sink through 

 the plain water only, and float upon that 

 portion which is saturated with salt, appearing 

 to be suspended in a very remarkable and 

 curious manner. 



CHAMELEON FLUID. 



Make an infusion of logwood in the same 

 manner that tea is made ; the only precau- 

 tion is, not to make it in a metallic vessel. 

 Now pour out some of the logwood-tea into 

 four wine-glasses ; to one of the glasses add 

 a few drops of vinegar, to another put in a 

 few grains of alum, and into the third glass 

 a few grains of green copperas (sulphate of 

 iron) ; in the fourth glass the liquid may be 

 left of its natural colour, while the three 

 former will be changed respectively into red, 

 blue, and black. An infusion of red cabbage 

 will change in the same manner, and becomes 

 green by the addition of a few drops of 

 hartshorn, i.e., ammonia. 



COLOTJEED FLAMES. 



Few experiments are more interesting to 



the young philosopher than the production 

 of different flames. The best material for 

 burning to exhibit these effects is spirits of 

 M'ine, the substances to produce the colours 

 being previously dissolved in it. Thus, to 

 produce a greenish-blue flame, put into a 

 vial a table-spoonful of spirit, and then shake 

 in two or three pinches of sulphate, nitrate, 

 or chloride of copper ; twist a piece of lamp- 

 cotton round the end of a wire, and dip it 

 into the mixture ; then set it on fire, and the 

 beautiful colour is at once produced. For a 

 pale-yellow flame, put into the vial of spirit a 

 tea-spoonful of common table-salt. The flame 

 produced by spirit containing salt has a very 

 singular effect upon colours, especially red, 

 which, if there be no other light in the room 

 while this mystic flame is burning, appears 

 of a blue-black. All other colours, such as 

 the various tints of ladies' dresses, undergo a 

 chameleon change. " Rosy cheeks" and 

 " coral lips" are metamorphosed to a ghastly 

 slate colour, creating much merriment. Bed 

 or scarlet flame is produced by dissolving in 

 the spirit a small portion of nitrate of stron- 

 tian or chloride of calcium. All these sub- 

 stances may be procured from any operative 

 chemist. The strontian comes from Argyle- 

 shire, in Scotland, and takes its name from 

 Strontian, the town in the neighbourhood of 

 which it is found. There are many other 

 substances which colour flame in a like 

 manner, such as boracic acid, chlorate of 

 potash, etc. ; but those previously named 

 produce the most striking effect, the colours 

 being modified by mixing the chemicals. 



INSTANTANEOUS CEYSTALLIZATION. 



All experiments for the production of 

 crystals are both interesting and beautiful ; 

 they show that all matter wiU assume, under 

 favourable circumstances, a definite and regu- 

 lar form or shape. Crystallization is a species 

 of vitality belonging to, and inherent in, what 

 are generally called unorganized earthy sub- 

 stances, perfectly analogous to the regular 



