FIBRES 357 



Ferrocyanide of thorium. A white precipitate is produced by the action of solution 

 of prussiate of potash oil salts of thorium. 



Ferrocyanide of tin. Pure salts of tin, whether of the per- or prot-oxide, give 

 white precipitates with ferrocyanide of potassium. 



Ferrocyanides of titanium. Solutions of titanates give a golden brown precipitate 

 when treated with solution of ferrocyanide of potassium. 



Ferrocyanides of uranium. The protochloride gives a pale, and the perchloride a 

 dark reddish brown precipitate with ferrocyanide of potassium. 



Ferrocyanide of vanadium. Salts of vanadic oxide give pale yellow, and of vanadic 

 acid rich green precipitates with prussiate of potash. 



Ferrocyanide of zinc cannot be prepared by precipitation. It may be obtained in 

 tl^e form of a white powder by the action of oxide or carbonate of zinc on ferro- 

 prussic acid. C.G.W. See "Watts's ' Dictionary of Chemistry.' 



FERROCYANOGEN, a compound radical, in which the metallic iron is an im- 

 portant constituent. See previous article, and Watts's ' Dictionary of Chemistry.' 



FERROUS SALTS. Salts of ferrous oxide or protoxide of iron. Thus green 

 vitriol may be called ferrous sulphate, instead of sulphate of protoxide of iron. In 

 like manner ferrous chloride is synonymous with protochloride of iron. 



FERRUGINOUS QUARTZ. A quartz stained by iron, an intermediate state 

 between quartz and jasper. See JASPER. 



FETT-STEIN 1 , Ger. (Fat Stone.} A variety of Nepheline, one of the Scapolite 

 family, so called from its resinous lustre. 



FEVERFEW. The popular name of the Pyrethrum Parthenium, much used 

 amongst the peasantry as a remedy for fevers. It contains some tannic acid, and 

 has been employed in Germany in tanning and currying leather. The Pyrethrum 

 officinale is the Pelletory of Spain. See PYRETHRUM. 



FIBRES, or FIBROUS BODIES. From time to time numerous grasses, fibrous 

 barks, and other substances of a similar character, have been introduced into com- 

 merce ; a few of these only have been found available for manufacture. It is, however, 

 deemed of interest to describe briefly some of these. Some of the more important 

 vegetable fibres will be fully noticed under their respective heads. (See COIR ; ES- 

 PARTO ; FLAX ; HEMP ; PHORMIUM, &c.) 



China Grass. This fibre is obtained fromUrtica (Bcehmeria) nivea^ which grows abun- 

 dantly in China, and in various parts of our Indian empire. The samples which have 

 been imported are principally obtained from Canton and Hong-Kong. In 1 849, Messrs. 

 Wright and Co. obtained a patent for the preparation of this fibre. Their process 

 consisted essentially- of boiling the stems in an alkaline solution, after they had been 

 previously steeped for 24 hours in cold water, and for 24 hours in water at 90 Fahr. 

 The fibre is then thoroughly washed with pure water, and finally subjected to the 

 action of a current of high-pressure steam till nearly dry. 



Callooee Hemp or Ehea. This fibre is usually confounded with China grass ; but 

 there is little doubt they -a re obtained from two different kinds of urtica; the China 

 grass from the Urtica nivea of 1 Willdenhow ; the Callooee Hemp, Kalmoi, or If ami, of 

 Sumatra, and the Shea, from the Urtica tenacissima of Eoxburgh. The plant pro- 

 ducing the Callooee hemp was introduced from Bencoolen to Calcutta in 1803, where, 

 under the care of Dr. Koxburgh, it was for many years cultivated in the Botanic 

 Gardens. In 1814, a quantity of the Callooee hemp was imported into England, and 

 properly tested ; its-practical value was thought so highly of, that the Society of Arts 

 awarded a silver medal to Capt. James Cotton, of the East India Company, who in- 

 troduced it. ' The chief obstacle which interfered, however, with its use, was the 

 difficulty which was found to exist in the preparation of the fibre from the stems of 

 the plants ; none of the processes usually adopted with flax or hemp were found to 

 be at all suitable to them ; and the rude, wasteful, and imperfect means employed by 

 the natives in preparing the fibre for the manufacture of twine, thread, and fishing 

 nets, by the mere process of. scraping, were wholly inapplicable on a large scale, 

 and gave besides only a very inferior result. When macerated or retted in water, it 

 was found that the fibre itself was more easily destroyed than the glutinous matter of 

 the stem. During the last forty years, various attempts have been made to devise a 

 good and cheap process for preparing this fibre, but hitherto without much success ; 

 and consequently, till quite recently, the cost of the fibre was such as to preclude its 

 being brought into the market .as a substitute for flax. But recent investigations have 

 shown that the Urtica tenacissima and the U. heterophylla maybe obtained in almost un- 

 limited quantities in various, parts of India ; and a process which has been lately 

 patented appears, to a very great extent, to have removed the practical difficulties 

 which previously stood in the way of its employment by manufacturers ; so that in a 

 few years it is probable that the Callooee hemp will constitute an important addition 

 to the fibrous materials employed in the arts,' Jurors' Report, Great Exhibition, 1851. 



