192 



SCIENCE. 



[Vol. XII. No. 2c 



Sorting Colored Wools when Blindfolded. 



Your reviewer considers that the experiments of Professor Fon- 

 tan, in which an hypnotic subject sorted colored wools with his 

 fingers when his eyes were completely covered, are simply incredi- 

 ble. It is true that they are so hard to believe in, that a single in- 

 stance can produce scarcely any effect at all ; but they cannot be 

 considered as absolutely incredible, in view of the fact that Prof. 

 Vitus Graber has shown that so thick-skinned an animal as the 

 cockroach re-acts to colors when his antennse have been removed 

 and his head has been covered with a thick coating of black seal- 

 ing-wax. M. 



Classification of Soils. 



In the highly interesting summary of the forthcoming report of 

 Director Powell, given in the issue of Science of Sept. 28, it is 

 stated that in this report is announced a " new, scientific, and sys- 

 tematic classification of soils," a summary of which is then given. 



Your correspondent is evidently unfamiliar with the standard 

 and current literature of the subject. Director Powell simply 

 adopts, for the purposes of geological field-work, a " working 

 •classification of soils," based upon their geological genesis. It is 

 scientific and systematic, but certainly not new to any of those who 

 have been concerned in such work, or have mapped its results from 

 the standpoint of the geologist. Major Powell substitutes, perhaps 

 wisely, the terms ' endogenous ' and ' exogenous ' for the more 

 familiar ones of 'sedentary' and 'transported;' and instead of 

 ■classing lacustrine and marine soils under 'alluvial' as a general 

 head, he restricts the term ' alluvial ' to those soils formed by rtm- 

 ning water only. I doubt the advisability of the latter change, 

 ■unless we cease also to speak of lacustrine and marine alluvium, 

 ■using some other term for the general idea of genesis by recent 

 alluvion. 



Major Powell also apparently proposes to replace the old term 

 -' colluvial ' by that of ' overplacement ' soils. I doubt that even 

 from the geological standpoint this is an improvement, for within 

 this class must be placed the larger portion of the arable soils of 

 hill-lands (there being no other within which they can regularly fall); 

 and these certainly result more properly from ' coUuvion ' — i.e., a 

 -' washing-together ' and intermixture of the various materials on 

 the slopes — than from what may properly be termed ' overplace- 

 ,ment.' 



As a schedule stated by himself to be merely tentative and for 

 the purposes of field-work, and published only in an abstract made by 

 a third party. Major Powell's classification is not yet a proper subject 

 for extended comment. But it cannot but be a matter of congrat- 

 ulation that the subject of soils is now to receive close attention in 

 the field-work of the survey, and will doubtless thereafter be sub- 

 jected to such further elaboration as may be necessary to render 

 the results available for agricultural practice. 



E. W. HiLGARD. 

 Berkeley, Cal., Oct. 5. 



Recent Information from the Muir Glacier, Alaska. 



In my paper upon the Muir glacier, published in the A>nerzcan 

 fournal of Science iox January, 1887, I gave on pp. 11-12 a sum- 

 mary of the reasons for believing that the front of the glacier was 



■ retreating at a pretty rapid rate. Recent information confirms this 

 view in a striking manner. I learn through Captain Hunter that 

 ■upon June 27 last he established an observation station upon the 



glacier, and took accurate notes and measurements both then and 

 in his recent trip in September, and found that during the three 

 months of absence the glacier had broken off, and receded inland 



■ one-fourth of a mile. Whether this distance is regained by the for- 

 ward motion in the winter or not, remains to be seen. Doubtless 

 the captain can determine this when he returns next summer. Ac- 

 cording to my own observations during my prolonged visit in 1886, 

 the central point of the glacier, where it meets the water of the in- 

 let, remained nearly stationary, although great masses were repeat- 

 edly seen to break off from it, and sometimes it seemed during an 

 interval of a few days to have receded perceptibly, while at other 

 intervals it had regained its position. But from Captain Hunter's 

 observations this season, it would seem that the waste consequent 

 ■upon the formation of icebergs is greater than is supplied even 



by the rapid motion of the glacier (from sixty-five to seventy- 

 two feet per day), demonstrated by my observations to have existed 

 a mile or two back from the front. Captain Hunter also reports 

 that immediately in front of the ice his sounding-line ran out one 

 hundred and six fathoms without reaching bottom ; and, since the 

 ice rises about four hundred feet above the water, there must here 

 be a depth of more than a thousand feet of ice. 



G. Frederick Wright. 



Oberlin, O., Oct. ii. 



Chalchiuitl : A Note on the Jadeite Discussion. 



In his very valuable and interesting note on jadeite in Science 

 of Oct. 5, Dr. Brinton called attention to the fact that Bernardino 

 Sahagun had mentioned iziac chalchiuitl as being white chalchiuitl, 

 fine green, and quite transparent, and also says that the white chal- 

 chiuitl was obtained from quarries in the vicinity of Tecalco, which 

 he (Dr. Brinton) believes to be the modern Tecali. If such is the 

 case, it is very evident that this is the so-called Mexican onyx, 

 ' Tecali marble or onyx,' as it is sometimes called, which exists 

 there in veins, being in reality an aragonite stalagmite. Great 

 quantities of it were made into Mexican figures, ornaments, and 

 beads, which are found all the way from northern Mexico down to 

 Oaxaca. This so-called onyx is extensively quarried to this day, 

 forming one of our richest ornamental stones. 



The definition of qitetzal chalchiuitl — " precious chalchiuitl, white, 

 with much transparency, and with a slight greenish tinge, some- 

 thing lil<e a jasper " — is somewhat contradictory, if it was intended 

 for jadeite. A variety of green stones exist at present, and were 

 used in considerable abundance in ancient Mexico. Among eight 

 green stone objects which have been recently sent me as jadeite, 

 four are jadeite, one is a laminated serpentine, another is a greenish 

 quartz, and the other two are a mixture of white felspar and green 

 hornblende. 



In a string of beads there are four pieces of jadeite ; but all the 

 others were, as are the jadeite beads, in the form of rounded peb- 

 bles, drilled from both sides, and there are nearly a dozen different 

 substances in this string. The fact that these jadeite beads were 

 strung in with the others, apparently without any order except that 

 they were graded to taper toward each end, points very strongly to 

 the conclusion that they were found with the other pebbles in a 

 brook, and, being of the correct size, had been drilled the same as 

 the others, although very much greater in hardness. The question 

 is, are these pebbles a part of the tribute mentioned in the Codex 

 Mendoza referred to by Dr. Brinton } If so, they must have existed 

 in some abundance ; and they have not been reworked from other 

 objects, as are the larger pieces, like the Costa Rican celts. Can it 

 be that the large ones came from lower Mexico, and, after being 

 used as implements, were traded off, but being green stones, which 

 have been given the preference the world over by savages and bar- 

 barians, were made into votive objects ? Among other green stones 

 used by the ancient Mexicans are green jasper, green plasma, ser- 

 pentine, as well as a fine-grained green shale and this Tecali marble, 

 often of such a rich green that at a glance it could be mistaken for 

 jadeite. 



Dr. Brinton's theory that Vilalta (Zoochila), in the State of 

 Oaxaca, is the possible home of large pieces of jadeite, if it exists in 

 Mexico, is a good one, since some of the largest jadeite ornaments 

 known, including the great sixteen-pound votive adze, were believed 

 to have come from that district, and it was from a quantity of peb- 

 bles from one of the streams of this region that the writer identified 

 yellow and blue sapphire almost as pure as the Ceylonese, being 

 one of the only materials with which jadeite can be worked. 



Dr. Meyer is quite right when he calls the Nephritfrage at pres- 

 ent a chemical problem ; for the mineralogist, by analysis and with 

 the microscope, can readily distinguish the many substances of one 

 kind or another that are sold as and called jade even by the Chinese, 

 among which are jadeite {feitsiii, or imperial jade), jade or nephrite, 

 green avanturine, green plasma, light-green jasper, green horn- 

 blende, serpentine, agalmatolite artificially stained green, and in 

 one instance even green-and-white glass, which last material was 

 presented as jade by a Chinese official to an American lady. 



George F. Kunz. 



New York, Oct. 15. 



