Oct. 1, 1865.] 



SCIENCE-GOSSIP. 



223 



silicified, and stand out in relief, while tlie mass of 

 tlie rock is composed of sediment witli foramini- 

 feral and eucrinital debris. The coral-rag forms a 

 reef in some parts of Wiltshire, but it is rarely 

 seen in section ; the corals are obtained as stones 

 from the ploughed fields. 



" The conversion of a limestone coral reef into 

 Dolomite becomes comparatively easy of belief, since 

 Mx. Sarby has shown that coral (like nacre) has the 

 constitution of aragonite, a much less stable com- 

 pound than calcareous spar. Pearly shells are never 

 preserved in calcareous rock, unless in a metamorphic 

 condition ; and the corals of the oolite formation are 

 usually silicified, like those of Tisbury, in Wiltshire, 

 and Mattheim, in Germany, or replaced by struc- 

 tureless calcite, full of sparry cavities. It is now 

 also well known that the masses of accumulated 

 chalcedony, called Beckite, found in the neighbour- 

 hood of Torquay, are Devonian corals, more or less 

 completely replaced by silica ; for they are some- 

 times hollow, and in other instances contain a 

 nucleus of fossil coral." A. C. 



OID TREES. 



'ILL you allow me to add to the list of aged 

 " Monarchs of the Forest " which appeared 

 m Science Gossip for August ? The Dragon tree 

 of Tenerifife is said by some writers to be tlie most 

 ancient of all known trees. Humboldt, when he 

 saw it, computed its age at one thousand years, but 

 I have read that the cypress of Soma, in Loml)ardy, 

 is the oldest tree of which we possess any record ; 

 that there is a chronicle extant at Milan which 

 mentions its being, in the time of that unbeliever in 

 omens who fell on the ides of March (Julius Caesar), 

 a full-grown tree — forty-two years before our Saviour 

 came upon this earth. 



There is in Japan a camphor tree w'hich the su- 

 perstitious in Sorrogi declare to have grown up 

 from the staff of Kobodarsi (a rather famed philoso- 

 pher, who lived in the eighth century), capable 

 of containing fifteen persons in its hollow. But 

 what is this to the coniferous WeUhujton'm (jigantea 

 of the slopes of Sierra Nevada ? The bark of this 

 tree, put in the form of a room, will hold forty 

 persons — not closely packed together, but seated, 

 with a piano for the benefit of the musical as well. 

 This room made of bark was exhibited in London 

 some years ago, when 150 little children were ad- 

 mitted, and the tree from which it was taken is said 

 to have been three thousand years old. Some 

 ninety trees of this kind are found, all within the 

 circuit of a mile, on the slopes of Sierra Nevada, 

 5,000 feet above the level of the sea, varying in 

 height from 250 to 300 feet, and in thickness, or 

 diameter, from 10 to 20 feet, the bark being from 

 12 to 15 inches iu thickness. 



A writer in the Gardeners' Chronicle says (or 

 rather said, a few years ago) that this tree only grows 

 ten inches in diameter in a period of twenty years. 



Then we have old trees in our own land — the oak 

 the chestnut, and others. Dryden assigns nine 

 centuries to the oak. 



The monarch oak, the patriarch of the trees. 

 Shoots rismg- up, and spreads by slow degrees ; 

 Three centuries he grows, and three he stays 

 Supreme in state, and in three more decays. 



Both the Bidl oak of Wedgenorth Park and the 

 Courthorpe oak of Colburn are said to be as aucient 

 as the Norman Conquest. Yf e have likewise Gospel 

 oaks— the "Four Evangelists and the Tv/elve Apos- 

 tles," so called because portions of the Gospel were 

 formerly rea.d uuder them on Holy Thursday. 



The Bentley oak and the Winfarthing are 

 believed to have been 700 years old when William 

 came over to conquer us; therefore Dryden's allotted 

 period of nine hundred years has been considerably 

 exceeded by them. 



There is a famous chestnut tree in Gloucester- 

 shire, at Tortworth, which has been standing since 

 the reign of Stephen (1150), and others at Dorking, 

 in Surrey, planted in 1377. 



Our yew trees, liliewise, are venerable. The 

 Ankerwyke yew, on the banks of the Thames, op- 

 posite Eunnymead, in Surrey, was an old tree when 

 Magna Charta was signed in 1251 ; it yet, I believe, 

 flourishes ; at any rate it was living and in green 

 leaf a few years ago. There is also at Cliefden 

 Woods a very ancient shell, I may call it, of a yew 

 tree, measuring nearly twenty-seven feet in diameter. 



Olive trees are deemed old by modern writers ; I 

 ought, probablj', to say long-lived, for in the environs 

 of Nice there is one considerably over 900 years 

 old ; and some authors assert that a few of the trees 

 on Mount Olivet are 2,000 years in age ; nay, more, 

 they say that many of thenr stood there eleven 

 centuries before the Christian era. There is no 

 doubt that olive trees still thrive on the rocky 

 mountains of Palestine, on the very spot called Ijy 

 Hebrew writers "the Mount of Olives," yet I do 

 doubt their being the self-same trees that grew there 

 in our Lord's time. 



A gentleman assured me yesterday that a tree in 

 Tasmania, of the gum tree kind, is both the largest 

 and the oldest in the world. Perhaps some of your 

 readers will tell us something of its history. 



Helen Watney. 



Inpusoeia. — The polishing slate of Biliu, iu 

 Prussia, forms a series of strata fourteen feet thick, 

 and is entirely composed of the siliceous shields 

 of 'Infusoria, of such extreme minuteness, that a 

 cubic inch of the stone contains forty-one thousand 

 millions of distinct organisms. — ManteWs Thoughts 

 on Animalcules, 



