10i9 



ZIN'C MANUFACTURE. 



ZI'NGIBER OFFICINA'LE. 



derangements, oxide of zitio is often serviceable, especially when com" 

 bined with conium. In the cramps of the stomach to which habitual 

 drjrakards are subject, it is very useful. 



Impure oxide of zinc is called tutty. It is sometimes used exter- 

 nally as a dusting powder, as a mild absorbent, on excoriations, and to 

 heal chaps and cracks in 'the skin. It is also used as an ointment. 

 Pure oxide of zinc forms an ointment of much value where a mild 

 astringent is needed, especially in the chronic inflammation of the 

 eyelids. 



Carbonate of zinc when impure is termed calamiue. This, after 

 being subjected to divers processes, is called prepared calamine. The 

 only use made of it is to form an ointment, which is most useful as an 

 application to burns, excoriations, and superficial ulcers. 



Sulphate of zinc is in small doses a very valuable astringent, tonic, 

 and antispasmodic ; in larger doses it is a very certain and speedily 

 acting emetic ; and in very large doses it is poisonous. It is the most 

 useful emetic in cases of narcotic poisoning, as it is not so apt to 

 inflame the stomach as tartarised antimony : but the stomach-pump is 

 preferable to either. 



The tonic effects are best seen in affections of the mucous mem- 

 branes. In the suffocative catarrh of aged persons, and the extreme 

 defluxions on the chest after influenza, sulphate of zinc affords a 

 valuable remedy : it must be given in small doses, as the sudden 

 suppression of the secretion may cause inflammation. Its utility is 

 increased by combining it with the compound rhubarb pill, or with 

 myrrh only. The use of the solution as an injection requires the 

 same caution. 



Acetate of zinc is possessed of nearly similar properties, but in a 

 weaker degree ; and as an injection, seems in some cases entitled to a 

 preference. 



Chloride of zinc, called also butter of zinc, is a powerful escharotic 

 >,r caustic ; this action results from its strong affinity for albumen and 

 gelatine, which principles it abstracts from the living tissues, and so 

 forms an eschar. Its powers in this way have bee* taken advantage of 

 troy parts affected with malignant diseases, such as cancer and 

 lupus, and to remove nsevi materni, or mother-marks. In none of 

 these in it to be resorted to unless they are very superficial. Deep- 

 seated cancer of glands can scarcely be removed by it, but other forms 

 are often successfully treated by it. (Walshe, ' On Cancer," p. 219.) 

 Properly diluted, chloride of zinc is most beneficially used to correct 

 the foHor from suppurating ears of children. 



Cyanide or cyanuret of zinc is a powerful antispasmodic and tonic. 

 No medicine is so potent in allaying irritability of the stomach, 

 attended with great debility. The dose must be small and often 

 repeated. Velerianate of zinc has lately been much recommended as a 

 remedy against tic-douloureux and other nervous affections. Where 

 the patients can tolerate the repulsive odour and persevere in its use, 

 it of ten proves very serviceable. 



Zinc pans have been much recommended for use in dairies, as the 

 milk speedily coagulates in them, and the quantity of cream is great : 

 but if the milk becomes sour while in them, the acid acts upon the 

 zinc, and forms unpleasant, though perhaps not poisonous compounds. 

 Upon the whole, white i>orcelain vessels, kept thoroughly clean, are the 

 best material for milk-vessels. 



ZINC MANUFACTURE. The mode of obtaining zinc from the 

 Kulphuret and other ores in explained in the article ZINC. As brought 

 to market, commonly under the name of spelter, it is a bluish-white 

 metal, having considerable hardness and toughness. The chief English 

 supply is from Flintshire and the Isle of Man; but the market is 

 mostly supplied from Upper Silicia, where the ore is smelted, and the 

 spelter sent for shipment from Dantzic, Stettin, and Hamburg : 

 shippers are willing to convey it freight-free, to serve as ballast for the 

 ships that bring German wool to England. Mr. Robert Hunt has 

 given the following aa an account of the British ores of zinc brought 

 up to the surface in 1857 : 



Cornwall 167i ton?. 4,697 



Devon 775 2,478 



Cardigan 1371 4,452 



Isle of Man 2917 10,772 



Cumbcil.tnil 492 697 



North Wiiltn 2060 7,887 



9290 30,983 



presenting an average of about 66. per ton. The largest mass of zinc 

 ever described was that which was displayed at the Great Exhibition 

 in 1851, and which weighed 16.000 Ibs. It was smelted from the ore 

 by Messrs. Detmold, of New Jersey, in the United States. There is a 

 vein of zinc-ore 9 feet thick, at a spot about 60 miles from New York, 

 and easy of access, as it is not far beneath the surface. The ore is 

 carried to Newark, in New Jersey, where it is converted partly into 

 metallic zinc, but mostly into zinc-white for house-painting. The 

 metal is separated from the other ingredients of the ore by a process 

 of vaporisation, as described in the article ZINC; but at Messrs. 

 Detmold's establishment some of the operations are conducted in a 

 remarkable way. A vapour, containing nearly all the zinc, is sent by 

 blast along pipes to a catchiny-hniuc, where it passes into enormous 

 hags of cotton 6 feet in diameter by ISO feet long; the gases pass 



through the meshes of the bag, while an oxide of zinc cools down t" 

 the state of a white powder, which is shaken out of the bag at intervals. 

 This is the mode adopted, not in procuring metallic zinc, but as the 

 preliminary stage in making zinc-white. The powder is either sold in 

 a dry state, in barrels containing 200 Ibs., or is ground up with linseed- 

 oil and sold in kegs. 



In reference to the zinc-white above mentioned, it may be observed 

 that the substance is recommended as a substitute for white lead in 

 house-painting not as being better suited in itself, but as being lea* 

 injurious to the workmen. Some persons, moreover, attribute to it- 

 much greater permanency, and other qualities superior to those possessed 

 by white lead. Linseed-oil and spirit of turpentine are mixed with the 

 zinc-white. Oil in good proportion gives it durability and efficacy of 

 covering the surface of the work ; in excess, it has a softening and 

 darkening effect. Turpentine in good proportion gives a ready fluidity 

 for spreading ; in excess, the paint becomes too transparent, and has a 

 tendency to pulverise. 



Metallic zinc is mostly used in the form of plates or sheets. When 

 heated to a certain temperature it becomes malleable and ductile, and 

 may then be rolled out to any convenient degree of thickness ; and 

 although brittle before this heating, the brittleness never returns after 

 the cooling. This is found to be a valuable property in zinc. In the 

 form of sheets, zinc is largely used for baths, cisterns, tanks, spouts, 

 pipes, chimney-pots, roofing, as also for plates for engraving, sheathing 

 for ships, and as one element in voltaic batteries. Being so much 

 lighter than lead, zinc is found to be very useful for roofing. The 

 joining of plates of zinc requires to be effected in a peculiar way. 

 [SOLDERING.] In the making of zinc door-plates, a sheet of rolled zinc 

 is cut to the proper size and shape, scraped to a clean surface, ham- 

 mered flat, planished with a broad and smooth-faced hammer, and 

 polished. Plates for zincographic engraving require, not a smooth, 

 but a fine granular surface ; they are rubbed first with ordinary sand. 

 and then with fine sifted sand and water applied by means of a woollen 

 rubber. 



Many modes of coating iron and other metals with a thin layer of 

 zinc have been described. Among these, one has been patented by 

 Mr. Alexander Watt, editor of the ' Chemist.' Steel or iron is pickled 

 in a solution of sulpho-muriatic acid, and then exposed to galvanic 

 action in a battery supplied with cyanide of potassium, liquid ammonia, 

 metallic copper, metallic zinc, hydrochloric acid, aud carbonate of 

 potash. This subject is further treated under TINNING. 



The chief use of zinc, perhaps, is as a compound in the formation of 

 brass. [BRASS.] 



In 1860, metallic zinc, under the name of spelter, was imported from 

 foreign countries to the extent of 24,000 tons. 



ZINCAMIDE. [AMIDES.] 



ZINC-AMYL. [OROANOMETALLIC BODIES.] 



ZINC-ETHYL. [ORGANOMETALLIC BODIES.] 



ZINC-METHYL. [OROANOMETALLIC BODIES.] 



ZINC-WHITE. [ZINC; Oxide of .] 



ZINCOGRAPHY. [LITHOGRAPHY.] 



Zl'NGIBER OFFICINA'LE (GINGER), Medical Properties of. The 

 native country of this plant seems unknown, though Goebel asserts 

 that it is Guinea. It is however extensively cultivated in China, Java, 

 and the East and West Indies. From the cultivated plant alone is the 

 ginger of commerce procured. Of this there are two varieties, the 

 black and white ; but some writers affirm that these are the produce 

 of two distinct species, while others ascribe the difference of appearance 

 to diversity of treatment after the rhizome is dug up. The rhizome, 

 or root-stock, is perennial, but it is only that of a young pknt, or the 

 annual shoots from an old one, which are met with in commerce. 

 When first dug up, the colour internally is red. Those procured the 

 first year are used fresh, or preserved in sugar, and constitute the 

 sweetmeat known as preserved ginger. This, when sent from the West 

 Indies, is in small, round, tender pieces ; when from the East, larger, 

 flat, and stringy portions : the former is preferred. 



Black ginger is stated to be the rhizome dug up, scalded in hot 

 water, and dried in the sun. White ginger is also scalded, and then 

 scraped to free it from the rind before it is dried, which last operation 

 is said to be effected by artificial heat, but probably mostly by the sun. 

 Both kinds are very liable to the attacks of an insect. To prevent 

 these attacks the rhizomes are dipped in a solution of lime, the whit 

 particles of which often adhere to the surface. To cause black ginger 

 to resemble the white, it is bleached, after its arrival in this country, 

 in a solution of chloride of lime, or exposed to the fumes of burning 

 sulphur. This impairs the activity of the article. 



Ginger occurs in commerce in pieces termed races, of various shapes, 

 but generally flattish, branched, lobed, or palmated, rarely more than 

 four inches long. The uuscraped has a wrinkled epidermis ; the 

 scraped is devoid of this covering. Jamaica ginger, which is most 

 esteemed in this country, occurs in races larger, rounder, aud thinner 

 than the other kinds ; externally of a yellowish white, internally of a 

 yellower hue. The taste is agreeably aromatic and pungent, but this 

 is lost with age, so that old pieces are worthless, as are also portions 

 which have been digested in alcohol to form etsence of ginger. Ginger, 

 when chewed, excites a flow of saliva ; the powder applied to the nos- 

 trils causes sneezing. The quantitative analysis of 100 parts of ginger 

 have been given by Bucholz : 



