STRONTIA 923 



Straw cannot be bleached by a solution of chloride of lime, as this preparation 

 always turns the straw yellow. For this purpose, a cask open at both ends, with its 

 seams papered, is to be set upright a few inches from the ground, having a hoop 

 nailed to its inside, about six inches beneath the top, to support another hoop with a 

 net stretched across it, upon which the straw is to be laid in successive handfuls 

 loosely crossing each other. The cask having been covered with a tight overlapping 

 lid, stuffed with lists of cloth, a brazier of burning charcoal is to be inserted within 

 the bottom, and an iron dish containing pieces of brimstone is to be put upon the 

 brazier. The brimstone soon takes fire, and fills the cask with sulphurous acid gas, 

 whereby the straw gets bleached in the course of three or four hours. Care should be 

 taken to prevent such a violent combustion of the sulphur as might cause black burned 

 spots, for these cannot be afterwards removed. The straw after being aired and 

 softened by spreading it on the grass for a night, is ready to be split, preparatory to 

 dyeing. Blue is given by a boiling-hot solution of indigo in sulphuric acid, called 

 Saxon blue, diluted to the desired shade ; yellow, by decoction of turmeric ; red, by 

 boiling hanks of coarse scarlet wool in a bath of weak alum-water, containing the 

 straw ; or directly, by cochineal salt of tin, and tartar. Brazil-wood and archil are 

 also employed for dyeing straw. For the other colours, see their respective titles in 

 this Dictionary. 



STREAM-WORKS. The name given by the Cornish miners to alluvial de- 

 posits of tin ore. 



STREET 3VIUD. This is a day of utilisation. We have already found out 

 plans for turning old clothes into money, for making our fields fertile by using the 

 refuse, and now the proverb ' cheap as dirt ' seems likely to lose all its force. ' The 

 Engineer,' speaking of the wet mud called ' Macadam milk,' which covers the streets of 

 Paris in the rainy season, says.: 'An adventurous individual has found an applica- 

 cation for this stuff, and at the same time, it is said, an income of 400. a year for 

 himself. He collects the il milk," allows it to settle in largo tanks, passes the precipi- 

 tate through silk sieves, and forms it afterwards into what we call Flanders bricks for 

 knife-cleaning, which sell at a franc each.' 



Upon this Mr. John Phillips remarks, 'that by a similar process, and from similar 

 material, stone or brick for cleaning or polishing steel and brass, and which is locally 

 known as "rotten stone," has been for many years, and still is, manufactured at the 

 Aller Works, near Newton Abbot. The roads in the neighbourhood which supply the 

 raw material are macadamised with flints, which especially adapts it for this purpose. 

 If credit is due anywhere for this utilisation of waste, let it not be monopolised by 

 France, but let Devonshire claim its fair share.' 



STRETCHING- MACHINE. Cotton goods and oilier textile fabrics, either 

 white or printed, are prepared for the market by being stretched in a proper machine, 

 which lavs all their warp and woof yarns in truly parallel positions. A very ingenious 

 and effective mechanism of this kind was made the subject of a patent by Mr. Samuel 

 Morand, of Manchester, in April 1834, which serves to extend the width of calico 

 pieces, or of other cloths woven of cotton, wool, silk, or flax, after they have become 

 shrunk in the processes of bleaching, dyeing, &c. The limits of this volume will 

 not admit of its description, The Specification of the patent is published in ' Newton's 

 Journal ' for December 1835. 



STRINGS, a miner's term. The name given by the Ccrnish miners to the small 

 filamentous ramifications of a metallic vein. 



STRINGY-BARK TREES. The great stringy-bark gum-trees of Australia 

 are various species of Eucalyptus. They are so called in consequence of the kn-k 

 separating in fibrous layers. 



STRIPPING LIQUID, SILVERSMITH'S, consists of 8 parts of sulphuric 

 acid and 1 part of nitre. 



STROIVTEYERITE. A sulphide of copper and silver, found in Siberia, Sileiia, 

 Chili, and Peru. 



STRONTIA (oxide of strontium, SrO), one of the alkaline earths, of which strontium 

 is the metallic basis, occurs in a crystalline state, as a carbonate (strontianite) in the 

 lead mines of Strontian in Argyleshire whence its name. The sulphate (celcxtine) is 

 found crystallised near Bristol, in New Red marl, and in several other localities ; 

 but strontian minerals are rather rare. The pure earth is prepared exactly 

 like baryta, from either carbonate or the sulphate. It is a greyish-white porms 

 mass, infusible in the furnace, not volatile, of a specific gravity between 3'0 and 4'0: 

 3 - 9231 (K(trften); having an alkaline reaction on vegetable colours, an acrid, burning 

 taste, sharper than lime, but not so corrosive as baryta, potash, or soda. It becomes 

 hot when moistened, and slakes into a white pulverulent hydrato, dissolves at 60 

 in 50 parts of water, and in much less at the boiling point, forming an alkaline 

 solution, called slrontia- water, which deposits crystals in four-sided tables as it cools. 



