Deckmukr 14, 188:).] 



SCIENCE. 



771 



carbonic dioxide, or 2.fi % of the carbonic oxide was 

 converted into carbonic dioxide. In a second experi- 

 ment, thirty litres of air containing 2.45 litres of car- 

 bonic oxide, when passed through the apparatus, in 

 twelve hours gave 04. (i milligrams of carbonic dio.xide, 

 or 1.3 %. The temper.ature varied between 20° and 

 20°. Bauniann found, further, that hydrogen per- 

 oxide was not produced when air was passed over 

 palladium hydrogen, although carbonic oxide was oxi- 

 dized to a small extent. He concludes, with Hoppe- 

 Seylcr, that this oxidation is due to the presence of 

 oxygen in its active condition. — {Berichte deutsch. 

 cliem. geseUxch., xvi. 2140.) c. F. M. 478 



Determination of the atomic weight of anti- 

 mony. — J. lioMgartz prepared metallic antimony 

 from autimoniuus chloride, which had previously 

 been purified by six or eight fractional distillations. 

 The melal was separated by electrolysis according to 

 Classen's method, and it was converted into the sul- 

 phide by heating witli potassic sulphide. Determina- 

 tions of sulphur in the purified sulphide were made 

 by Classen's method; viz., by oxidation with hydric 

 peroxide, and weighing the sulphuric acid thus ob- 

 tained as baric sulphate. The mean of twelve deter- 

 minations gave 120.193. — {Herichie deutsch. chem. 

 geselhch., xvi. 359.) c. F. M. [479 



AGRICULTURE. 

 Conductivity of soils. — Wagner has made a 

 somewhat extended investigation of the thermal con- 

 ductivity of various constituents of soils and of the 

 effect upon it of alterations in the structure of the 

 soil and in its moisture. The materials used were 

 quartz sand, kaoline, precipitated calcium carbonate, 

 ferric hydrate, peat extracted with acid and alcohol, 

 and artificial humus prepared from sugar. The 

 quartz was founii to be the best coiuluctor, and tlie 

 humus the poorest, while the other^mateiials occu- 

 pied intermediate positions. The differences were 

 small, however, and of little significance, compared 

 with those due to differences of lextme, compactness, 

 and moisture. Experiments with two natiu-al (cal- 

 careous) soils showed that heat was transmitted more 

 slowly in a loose soil than in the same soil compacted, 

 and that these differences were greater the greater 

 the water-content of the soil. The latter factor, in- 

 deed, seemed to have more influence than any other. 

 Its efifect is due, .according to the author, to the fact 

 that it is a somewhat better conductor than the air 

 which it replaces in the interstices of the soil. The 

 heat was transmitted horizontally, so that there was 

 little chance for the transmission of heat by convec- 

 tion. The effect of compacting the material was also 

 studied on the six soil-ingredients mentioned above; 

 and the compacted material was found to transmit 

 heat better than the loose, in every case except the 

 lunnus, of which the reverse was true. The con- 

 ductivity was found to increase with the size of the 

 particles or aggregates of which the soil was com- 

 posed. Observations were also made on the daily 

 variations of temperature at different depths in sand, 

 clay, and peat. The variations were greatest, and 

 extended to the greatest depth, in the sand. The 



peat stood at the opposite extreme, and the clay be- 

 tween the two; in these respects, their positions cor- 

 responding to their relative conductivity as previously 

 determined. — (Fomclir. ayr. i>liy.iili., vi. 1.) ii. P. A. 



[480 

 GEOLOGY. 



Lithology. 



The Maine building-stones. — It is well known, 

 that, at the time Dr. Hawes was attacked by the ill- 

 ness which terminated so fat.ally, he was engaged in 

 the microscopic study of the United States building- 

 stones. It has been hoped that some one would be 

 able to take up his unfinished work, and, in justice to 

 his memory, render him credit for all that he had 

 done. Whether this desirable work will ever be ac- 

 complished is a problem for the future. Meanwhile, 

 the Maine building-stones collected for Dr. Hawes's 

 work have been the subject of a recent paper by Mr. 

 G. P. Merrill. These rocks, together with much data 

 relating to their use, etc., were collected by Mr. J. E. 

 Wolff, now of the Northern transcontinental survey. 



Mr. Merrill classes these building-stones under 

 biotite granite, biotite muscovite granite, hornblende 

 granite, hornblende biotite granite, biotite gneiss, 

 biotite muscovite gneiss, diabase, olivine diabase, and 

 argillite or slate. Of the eighty-three (juarries in 

 Maine in 1SS0-S2, seventy-four are of granite or 

 gneiss. 



The granites vary in color from a light to dark 

 gray, and from a light pink to red. In texture they 

 vary from fine, even-grained rocks, to coarsely granu- 

 lar ones, containing orlhoclase crystals an inch or 

 more in length. 



The constituents are quartz, orlhoclase, plagio- 

 clase, biotite, or hornblende, with or without musco- 

 vite, apatite, magnetite, zircon, epidote, sphene, rutile 

 microcline, and iron pyrites. 



The paper is accompanied by descriptions of the 

 microscopic characters of the granites, which are of 

 value to all interested either in lithology or building- 

 stones. 



The gneisses are similar to the granite, and, so far 

 as the present writer's observations have gone, they 

 are of the same origin. 



Diabase, under the name of black granite, is quar- 

 ried at three localities in Maine, — Indian River in 

 Addison, Addison Point, and Vinalhaven. The first 

 locality produces a nearly black rock composed of 

 plagioclase, augite, magnetite, apatite, and secondary 

 hornblende and mica. The other localities produce 

 a similar rockj with the addition of olivine and chlo- 

 rite. 



It is a remarkable freak of fashion which renders 

 rocks of such undesirable composition so much sought 

 for, and extensively used, for poli.-^hcd monumental 

 and ornamental work used out of doors, for which 

 they are entirely unfit. This well illustrates the 

 wide-spread ignorance, even among architects, of 

 the properties of building-stones, even if New York 

 and Boston, coupled with Harvard university, did 

 not furnish striking examples. 



Mr. Merrill's remarks on the properties of building- 

 stones need to be received with caution, especially 



