34 



SCIENCE-GOSSIP. 



[.Feb. 1, 1866. 



In mounting crystals the great aim of the pre- 

 parer should be to obtain perfect and regular speci- 

 mens. These will always be of value as a reference 

 to the typical crystalline form of any salt. Most 

 salts, if their solutions are rapidly evaporated, form 

 a crystalline mass, of which the component crys- 

 tals are so conglomerated together that the normal 

 form is difficult, if not impossible, to be made out. 

 Hence the necessity for slow evaporation. It is a 

 good plan to prepare two or three slides, and, before 

 mounting, to select the one which has the most 

 perfect crystals. Of course (like everything else 

 connected with microscopy) mounting crystals re- 

 quires practice, and there is a certain knack which 

 can only be acquired by repeated operations, and 

 the observer must not be discouraged by frequent 

 failures. While on the subject of crystals it may 

 not be out of place to notice one other circumstance, 

 which, though not of any scientific importance, is a 

 source of pleasure to the observer, and deserves more 

 attention than is frequently given to it, viz., the 

 act of crystallization, which is very beautifully seen 

 under a low power with the aid of the polariscope 

 and selenite stage. The slide on which a drop of 

 the solution of the salt under examination has been 

 placed should be warmed and placed under the 

 microscope. As evaporation proceeds, delicate 

 forms are seen darting swiftly over the field, or 

 more leisurely pursuing their path, accompanied by 

 the most splendid play of colours, until the whole 

 field becomes one mass of crystals glowing with all 

 the colours of the rainbow. Sometimes minute crys- 

 talline points dart into view, and, gradually increasing 

 in size until they frequently join each other, form a 

 spectacle which cannot fail to fill the mind of the 

 thoughtful observer with wonder, and to raise ques- 

 tions as to what are the laws which govern the for- 

 mation of those beautiful shapes presented to his 

 gaze, and why these varied forms should dhTer. 

 The great questions respecting light and heat are 

 gradually approaching solution, and may not those 

 relating to the formation of crystals be solved by 

 some patient investigator ? 



Death-watch. — Mr. Smith lately called the 

 attention of the Entomological Society, to a query 

 recently put to him by a correspondent respecting 

 the so-called " death-watch." He was inclined to 

 think that the "ticking" said to be caused by 

 Atropos pidsatoriam was scarcely substantiated, 

 as he could not conceive it possible that so soft 

 and delicate a creature could produce any sound 

 whatever ; and, with reference to that supposed 

 to be made by Anohium, he thought it more 

 likely that this was caused by the insect's gnawing 

 the wood, rather than as being a special independent 

 sound, as was generally supposed. — Entomol. Hon. 

 Magazine. 



STARCH/ 



IT must be premised that in writing of Starch we 

 do not use that term iu its domestic application, 

 and that the Starch of the laundry is but one of 

 several forms of the substance known in science 

 under the general name of Starch, which includes 

 also sago, tapioca, arrowroot, corn-flour, and similar 

 alimentary substances. 



It was said by a noted lady-lecturer, Lola Montez, 

 some years ago, that " Starch makes the man," 

 alluding to the then prevalent fashion of wearing 

 starched collars, shirts, and other portions of male 

 attire, not to mention the starched petticoats and 

 other garments of the gentler sex, before the intro- 

 duction of crinoline. Her assertion is true in another 

 sense, for wheat is not inaptly termed the " staff of 

 life " in temperate zones, and rice in tropical regions; 

 and it is largely on account of their Starch that they 

 are of so much benefit to mankind. 



Of the history of Starch very little is recorded. 

 It appears to have been known to the ancient Greeks; 

 and Pliny attributes to the Islanders of Chio " the 

 discovery of the method of extracting it from wheat." 

 The Venetian traveller Marco Polo, who visited 

 China and some parts of the East Indies in the 

 thirteenth century, describes the method of extract- 

 ing it from the sago-palm. According to Eosbroke, 

 starches of various colours were imported into Eng- 

 land from Holland in 1564— that which was yellow- 

 being esteemed the best for ruffs and other articles. 

 In histories and novels— treating of the early part 

 of the seventeenth century — allusion is occasionally 

 made to the notorious Mrs. Turner, who, in addition 

 to dealing in spells and philtres, introduced into 

 Britain yellow-starched ruffs, &c. In the presence 

 of many women of fashion, this introducer of 

 starched linen made her exit on the scaffold at 

 Tyburn, rouged and dressed as if for a ball, and 

 wearing an enormous ruff stiffened with her own 

 yellow Starch. Despite her example, in a few 

 years after her exit, the fashion she had introduced 

 died out. 



It appears that much of the Starch used for stiffen- 

 ing the enormous ruffs worn by "the upper ten 

 thousand" of that period was procured from the root 

 of the Arum maculattim; for that quaint old botanist, 

 Gerard, writes : — " The most pure and white Starch 

 is made of the roots of cuckoo-pint ; but most hurtful 

 for the hands of the laundress that hath the 

 handling of it, for it choppeth, blistereth, and 

 maketh the hands rough and rugged, and withal 

 smarting." 



To the unaided eye, Starch, highly purified, appears 

 simply as a powder more or less white, and some- 

 times with a glistening aspect. Under the micro- 

 scope, however, this powder is seen to consist of 

 granules of various forms and sizes, and on many of 

 them is perceived, either in the centre or near one 



