458 



SILKWORM OUT 



SILURIAN SYSTEM 



wooded tree growing in India, Banna, Java, and 

 North Australia. Its fibre is called simul. An- 

 other of these trees is Kripdendrun anfrnctuosum, 

 which is found in tropical cocntries of both hemi- 

 spheres, and which yields the fibre known in India 

 as rapok, Cochlospermum gtasyvium, a small 

 Indian tree, also yields a silk-cotton. A beautiful 

 fibre of this kind is obtained in the \\f ' Indies 

 from Orhroma luyoiius. Vegetable silk, which, like 

 silk cotton, is only suitable for stuffing, is the 

 covering of the seeds of Chorisia tpeciosa, a Brazilian 

 tree. 



Silkworm <.llt. a material used by anglers 

 for dressing the hook-end of the fishing-line. It 

 consists of the drawn-out glands of the silkworm 

 at the time it is about to spin its cocoon and when 

 these glands are fully distended. The worms are 

 immersed for twelve or fourteen hours in strong 

 vinegar, and then taken separately, and pulled 

 asunder. The skilled operator knows by the 

 strength of the silk-gut it the soaking in vinegar 

 has been sufficient, and if so he lays nold of the 

 ends of the two silk-glands and draws them out 

 gently to the proper length and so the gut is 

 formed. He then stretches a number of these 

 lengths separately across a board, fixing them at 

 each side or end by slits or pins, after which they 

 are exposed to the sun to dry. Silkworm gut is a 

 very strong material It is prepared in Italy and 

 Spain. 



Sillery, a village of 400 inhabitants in the 

 French department of Marne, near Kheims, famous 

 for its Champagne (q.v.). 



Silliiii:in. BENJAMIN, American physicist, was 

 born at North Stratford (now Trumbull ), Con- 

 necticut, August 8, 1779. His father was a 

 colonial jndge, and a brigadier-general in the war 

 of independence. He graduated at Yale in 1796, 

 was appointed a tutor in 1799, and was admitted 

 to the bar in 1802, hut soon after received from the 

 college the appointment of professor of Chemistry, 

 and proccedea first to study this subject, attending 

 lectures on chemistry for three years at Philadelphia, 

 mid in 1805-6 at Edinburgh (on geology also) and 

 London. His chair he filled till 1853, and for two 

 years longer lectured on geology. In the course of 

 many experiments in 1822 he first established the 

 fact of the transfer of particles of carlion from the 

 positive to the negative pole of the voltaic battery. 

 From 1 808 le delivered popular lectures on chemistry 

 and geology in many parts of the country, and 

 inicrcsied iii these subjects many who afterwards 

 became among the foremost of American scientists. 

 In Is to Professor Silliman was elected the first 

 president of the American Association of Geologists 

 and Naturalists since grown into the American 

 Association for the Advancement of Science. In 

 1818 he founded tin- American Journal of Science, 

 Ix-tter known as Sillinutn't Journal, of which he 

 was for twenty years the sole and for eight more 

 the principal editor. In 1830 he published a text- 

 iMMik on chemistry ; he edited several editions (if 

 Bakewell's <;,,,/i,</i/ and of Henry's I'hnnixti-i/ : ami 

 in 1853 he published a Xnrmtire of a Visit to 

 Europe in 1851 ( his Journals of Travels in Eng- 

 land, Holland, and Scotland had appeared as early 

 as 1810). He died 24th November 1864, at New 

 ll.ivi-n. where a bronze statue has been erected 

 < 1884) in the college grounds. See the Life by (. 

 P. Fisher (I MO i His son, Benjamin (1816-85), 

 :i Ntcd his father from 1837, in 1847 founded the 

 Yale (since 1860 the ' Sheffield ') School of Science, 

 and was its professor of Chemistry till I860, except 

 in 1849-54, when he held a chair at Louisville. He 

 was professor of Chemistry at Yale from 1854 in 

 the college till 1870, in the medical department 

 till his death. His researches were chiefly in 



applied chemistry and in mineralogy. From 184A 

 to 1885 he was co-editor of the Journal of Science, 

 and he published very popular manuals of chemistry 

 anil of physics, and a volume on American Contri- 

 bution* to Chemistry ( 1875). 



Silloth, a seaport and watering-place of Cam- 

 l>erland, on the Sol way Firth, 20 mites W. of Car- 

 lisle. Prior to the opening of the railway in 1856 

 it was a mere hamlet, but it is now of growing 

 importance, with good docks opened in 1857-85. 

 Silloth, which commands a fine view, is much 

 resorted to for sea-bathing, the climate being mild 

 and salubrious, and considered highly favourable 

 for those affected with pulmonary complaints. 

 The mean annual temperature is 49* 1', being i In- 

 same as that of Worthing (q.v.) on the south coast 

 of England, and only 1 below that of Torquay. 

 Pop. (1861) 1521 ; (1881)2116; (1891)2600. 



Silo. See SILAGE. 



Siloaill, a great rock-cut pool to the south-east 

 of Jerusalem, with a second or lower reservoir con- 

 nected with it by an aqueduct. See JERUSALEM 

 and map ; and for the ancient Siloam inscription 

 describing the making of a tunnel from a spring to 

 the pool, found in the tunnel in 1880, see INSCRIP- 

 TIONS, Vol. VI. p. 159 ; HEBREW LANGUAGE. VoL 

 V. p. 614. 



Siliirrs. an ancient people inhabiting the 

 south-east of South Wales and the adjoining 

 English area Glamorgan, Brecknock, Monmouth, 

 Radnor, Hereford. They were a dark and curly- 

 haired race, and were probably of a non-Aryan 

 stock Iberian or Euskarian though ultimately 

 Celt icised in language and manners. Less civilised 

 than their British neighbours, they were more war- 

 like, and offered fierce resistance to Ustorins 

 Scapula and the other Roman commanders who 

 invaded their country. See WALKS, BASQUES, 

 CELTS ; Elton's Origins of English History ( 1882), 

 Rhys's Celtic Britain (1882). 



Silurian System, a name given by Murchison 

 in 1835 from the Silures (q.v.) in South Wales, 

 where this system is well developed. The sedi- 

 mentary strata consist principally of grite, slates, 

 dark shales, flagstones, sandstones, ana conglomer- 

 ates, and interltcdded with these occur occasional 

 calcareous bands, and more or less lenticular beds of 

 limestone. The following table gives the succes- 

 sion of the Silurian system of Britain : 



{Ludlow Group. 

 Wenlock Group. 

 Upper Llandovery Group. 

 f Lower Llandovery Group. 

 T _ , a.. .. i Bala and Caradoc Group. 



LOWER twetlim...A L | Rm , ejlo Groop . 



VArenlg Group. 



The strata attain a thickness of more than 20,000 

 feet, and have a wide distribution. In Wales the 

 basement beds rest conformably on the upper mem- 

 bers of the Cambrian system, while a well-marked 

 unconformity separates the Lower from the Upper 

 Silurian. Silurian rocks are exposed at the surface 

 in many of our upland areas : thus, they form a 

 large part of the high grounds of Wales, West- 

 morland, and Cumberland, and the major portion 

 of the Southern Uplands of Scotland, and they like- 

 wise extend into the Scottish Highlands. In the 

 hilly parts of Ireland they are also well ileveloiied 

 at the surface ; nor can there be much doubt that 

 the same strata, buried under younger systems, 

 extend throughout the larger part of the British 

 Islands. The deposition of the Lower Silurian 

 was marked by the appearance of considerable 

 volcanoes in Wales, Westmorland, Ayrshire, and 

 the south-east of Ireland. 



On the continent of Europe Silurian strata have 

 an extensive development. They occupy large 



