SCIENCE. 



555 



was first covered by this incrustation of limestone, but 

 in the course of time was completely buried in the 

 thin, ribbon-like layers of this stalagmite. Then the 

 floor of the cave was broken up, and the detached piece 

 containing this specimen was carried here by water, or 

 ice, or both, and here it has remained imbedded in this 

 blue clay till all of the alluvium has been deposited. 

 Several arrow-points have been found buried seven or 

 eight feet below the surface of the earth. I have care- 

 fully examined two of these finds. They were buried in 

 a tough, compact clay. They were found by workmen 

 while cutting into the hillside and grading the public 

 roads. A small arrow point was found by a friend of 

 mine while digging a well. It was twenty-four feet 

 below the surface of the earth. It is a well-made and 

 beautiful arrow-point, and my friend will not part with 

 his valuable specimen. 



FRENCH ACADEMY OF SCIENCES. 

 August 8, 1 88 1. 

 Mineralogy. — M.Klein presents a communication on 

 different solutions of very great density, which can be ad- 

 vantageously utilized in laboratories to separate pulverulent 

 mineral particles from foreign bodies. The salts em- 

 ployed by M. Klein are the tungstoborates of cadmium, 

 nickel and cobalt. The density of the solutions of the 

 last two salts is 3. 4 ; yet M. Klein prefers to them the 

 solution of tungstoborate of cadmium, whose density is 

 only 3. 2, but which is quite transparent, while the others 

 are very colored. The tungstoborate of cadmium can, 

 besides, be obtained in crystals ; it melts at a temperature 

 of 75 , and becomes a transparent liquid, whose density is 

 3.6. 



Physics. — M. Ancelin described a method of heating 

 intended to replace foot-warmers of water. His system 

 is based on the fact that every body which passes from a 

 liquid to a solid state gives off its latent heat of fusion. 



M. Ancelin encloses some acetate of soda in a metallic 

 vase, which is then heated to a temperature of about 8o°. 

 Then left to itself, the apparatus cools little by little to 

 about 59° ; the acetate of soda then commences to 

 solidify, and gives off its latent heat. While the solidifi- 

 cation continues, the vase remains at the same tempera- 

 ture. Boilers heated in this way will remain hot four 

 times as long as by the use of water, about twenty to 

 twenty-two hours. 



Extraction of Sulphur.— M. Dubreuil, who has 

 devised a new method for extracting the sulphur of Sicily, 

 announces that he has found in the mother waters of the 

 salt marshes of Palermo, charged with chloride of mag- 

 nesium and boiling at 120 , a suitable substance to 

 separate from the sulphur the earthy bodies which ac- 

 company it. 



FOR the unities of electric measures there are adopted 

 the fundamental unities — centimetre, gramme, second, 

 and this sys'em is briefly designated by the letters C. G. 

 S. The practical units, the ohm and the volt, will retain 

 their present definitions; the ohm is a resistance equal to 

 10 s absolute unities (C. G. S.), and the volt is an electro- 

 motive force equal to io 9 absolute unities (C. G. S.). 

 The practical unit of resistance (ohm) will be represented 

 by a column of mercury of 1 square mm. in section at 

 the temperature of o' 1 C. An international commission 

 will be charged with ascertaining for practice, by means 

 of new experiments, the height of this column of mer- 

 cury representing the ohm. The name ampere will be 

 given to the current produced by the electromotor force 

 of 1 volt in a circuit whose resistanse is 1 ohm. Coulomb 

 is the quantity of electricity defined by the condition 

 that in the current of an ampere the section of the con- 

 ductor is traversed by a coulomb per second. Farad is 

 the capacity defined by the condition that a coulomb in 

 a condenser, whose capacity is a farad, establishes a dif- 

 ference of potential of a volt between the armatures. 



COMET (g) 1881, SWIFT. 

 At eleven o'clock last evening, Director Lewis Swift, 

 of Warner Observatory, discovered the seventh comet of 

 the year in the Constellation of Cassiopeia in a line be- 

 tween Polaris and the great cluster in Perseus, a tr fle 

 nearer Polaris It is nearly round, faint, has a slight 

 central condensation, but no tail is yet visible. Its right 

 ascension is one hour and fifty minutes, (1 h. 50 m). 

 Declination north seventy-one (71) degrees, and its mo- 

 tion slow westward. Estimated diameter, about four min- 

 utes. As the comet of 1812 is anticipated from this 

 quarter, it may be the great Pons Comet. This makes 

 the sixth comet discovered in this country since May 1st, 

 Swift getting the two hundred dollar Warner prize twice. 

 The fifteen hundred dollars given in comet prizes during 

 the past twelve months by Mr. Warner has evidently 

 given an extraordinary impetus to astronomical study in 

 this country. Director Swift, of the Warner Observatory, 

 will visit Egypt, by the generosity of the founder of the 

 Observatory, in December, 1882, to observe the total 

 eclipse of the sun and verify his celebrated discovery of 

 an intra-mercurial planet in 1878, which has been so 

 much disputed by astronomers. C. S. Whittlere, 

 Sec'v- Roch. Astro. Society. 

 Warner Observatory, Rochester, 

 N. Y., November 17, 1881. 



COPYING INK FOR READILY TRANSCRIBING 

 LETTERS WI THOUT A PRESS. 



A paper on this subject by Professor Attfield, F.R.S., 

 &c, was read at the last annual Pharmaceutical Confer- 

 ence at York, England. The author stated that for the 

 past thirteen years all letters, reports, &c, that he had 

 written had been transcribed into an ordinary thin-paper 

 copying-book with no more effort than was employed in 

 using apiece of blotting-paper. It had only been neces- 

 sary to place the page of writing, note size, letter size, or 

 even foolscap, in the letter-book, and use a leaf of the letter- 

 book just as one would use a leaf of blotting-paper. The 

 supeifluous ink that would go into blotting-paper went 

 on to the leaf of the letter-book, and, showing through 

 the thin paper as usual, gave, on the other side of the 

 leaf, a perfect transcript of the letter. Any excess of ink 

 on the page, either of the letter or of the copying pap^r, 

 was removed by placing a sheet of blotting-paper between 

 them and running one's hand firmly over the whole in 

 the ordinary manner. 



This ready transcription was accomplished, as would 

 be anticipated, by using ink which dried slowly. Indeed, 

 obviously, the ink must dry sufficiently slowly for the 

 characters at the top of a page of writing to remain wet 

 when the last line was written, while it must dry suf- 

 ficiently fast to preclude any chance of the copied page 

 being smeared while subsequent pages were being cov- 

 ered. The drying must also be sufficiently rapid to pre- 

 vent the characters " setting off," as printers term it, 

 from one page on to another after folding. 



The author then alluded to some difficulties at'ending 

 the employment of the ink which had prevented its be- 

 coming an article of wholesale trade, but, he said, any 

 chemist and druggist could make it and sell it, giving 

 directions for use 10 customers. He himself had used it 

 from year's end to year's end without any trouble what- 

 ever. It would be part cularly useful to professional men 

 and private persons. 



The principle of the method of preparat on consisted 

 in dissolving a moderately powerful hygroscopic sub- 

 stance in any ordinary ink. After experimenting on all 

 such substances k'nown to him, he gave the preference to 

 glycerin. Reduce, by evaporation, ten volumes of ink to 

 six; then add four volumes of glycerin. Or manufacture 

 some ink of nearly double strength and add to any quan- 

 tity of it nearly an equal volume of glycerin. 



