Science Notes.

New Zealand Tablet, Volume XXV, Issue 28, 12 November 1897, Page 5

Science Notes.

PREPARATIONS FOR THE NEXT ECLIPSE.

The principal English astronomers have now mopped out their stations for the eclipse of January next along the line of totality Grossing India in a south-westerly direction. It is desirable for the proper record of the phenomena, that the observations should be approximately continuous, so as to be reciprocally complementary. Sir J. Norman Lockyer and Mr. Fowler will establish themselves at Ratnagore on the west coast. The Astronomer Royal, Dr. Common, and Professor Turner will take up their position at a point where one of the two principal railways from Bombay to Poona is crossed by the shadow track, and Professor Newall will station himself at Wardha, where, with a large spectroscope, he will seek to estimate the rotation of the corona by the spectroscopic displacement of its lines.

THE BURNING TREE OV INDIA

There has lately been adde 1 to the collection of plants at the botanic gardens at Madras. India, a specimen of a strange tree, writes an East Indian correspondent to London. It is in size .scarcely more than a bush, but other individuals of its species n.ro known to have attained, in their habitat in the H'malaya,-, Bjrmah and the Malacca Peninsula, the dimensions of a large tree, from fifty to seventy-five feet in height. The Madras specimen is surrounded by a strong railing which bears the sii>n : '-Dangerous: all persons are forb dden to touch tho leaves or branches of this tree." It i?, therefore, a forbidden tree in the midst of the garden, but no one is tempted to touch it, for it is known to be a •' burning tree." This name is a misnomer, for the tree stings rather than burns, Beneath the leaves there are stings comparable to those of nettles, which, when touched, pierce the skin and secrete a fluid which certainly has a burning effect. The sting leaves no outward sign, but the sensation of pain exists sometimes for months, an 1 is especially keen on damp days, or when the place which has been wounded is plunged in water. The natives in the part of Burmah where this tree grows are in such terror oi it that they fly when they perceive th>) peculiar odour which it exhales. If they happen to touch it. they fall on the ground and roll over and over on the earth with shrieks. Do\'s touched by it yelp and run. biting and tearing the part of the bo-ly which has biv'n touched. A horse which had been in contact with a burning tree ran liko a mad thing, biting everything and everybodj' that it could reach. A missionary at Mandalay, who investigated a leaf of the plant with his forefinger, suffered agony for several weeks and for ten months felt occasional pains in his finger. Tin: philosopher's stone at laht. If the accounts in the New York Tnhunr of Dr. Emtncns's success in converting siher into tjold should be substantiated by further inquiry, the Wth century may Ijoi-t, a,-, its crowning achievement, of having realised the visions oc medieval alchemy in its search for the philosopher* stone. Tne discoverer of the process, a trained chemist, has since April dcpo-iteJ in the jKsay Office of New York seven ingots, weighing froms-oven to 17 ounces each, which have been examined and reported on by experts. They are declared to consist of a mixture of gold and sihe>\ and to contain from twothirds to three-fifths of the fOlf 01 mer, while Dr, Emmuiis avers that practically the only material used in their production was a quantity of Mexican dollars, containing an alloy of a tenth of copper, but no gold. This mixture he finds m some way to iaoilitatethe process of conversion, the agent of which is enormous mechanical pressure. Of course until the process is conducted under the eyes ot disinterested witnesses its genuineness cannot be accepted as proved, since as yet we have only the discoverer's tj/*r <h.i it to vouch for it, but it is, in any case, an interesting subject of speculation. A pressure of 2M tons to the square inch, which l)c. hnunens hopes to raise to MOO. is exercised for 10 days or a week at a time, in what ho calls a "force

engine." Faint flecks and streaks of yellow first appear in the white metal, until the former becomes the prevailing colour, and there is a stage of the process in which he considers it to form an intermediate substance which he calls argentaurum. When the final transmutation takes place this substance disappears, and the percentage that is not transformed into gold reverts to its original state of pure silver. Gold would thus be shown to be only a condensed form of silver, a supposition in which there is no inherent impossibility. The two substances are in one sense closely connected, and are placed by Professor Mendeleef in a class, comprising also sodium and copper, between the members of which a certain relationship is established by the ratio between the figures representing their atomic weights. There is, however, a gap in the series brtween gold and silver, and Dr. Eminons conjectures, although it remains to be experimentally investigated, that his intermediate metal, argentaurum, may supply the missing link m the chain. Up to the present he has only succeeded in transmuting five or six ounces of metal at a time, but with a greater number of machines of course the quantity treated could be increasud. Another important point at to which we have no information, is the cost of the process. An essential distinction between tho two metals is shown by the diffcreuue of their chemical affinities, or power of entering into combination with other substances.