Vol. XXn. No. 3.] 



POPULAR SCIETsTCE ITEWS. 



41 



The editorial chair left vacant by the death 

 of Dr. Nichols will not soon be filled by one 

 possessing the same power of placing the dry 

 facts of science in a clear and attractive form 

 before the unscientific reader, or of showing 

 the intimate connection between its funda- 

 mental principles and the affairs of every-day 

 life. It is, however, onl}- proper to state that 

 the management of the Popular Science News 

 will continue in the same hands as heretofore. 

 During the last j'ears of his life Dr. Nichols 

 frequently contributed to its columns, but left 

 the actual editorial management to his associ- 

 ates ; and they feel confident, that, with the aid 

 furnished by the numerous eminent scientists 

 who have promised to contribute to its columns 

 in the future as in the past, they can continue 

 to conduct the paper in a manner worthy of its 

 honored founder. 



Professor Asa Gbat of Harvard Univer- 

 sity died at his home in Cambridge on the 

 30th of January, at the age of 77, after an 

 illness of several months. Professor Gray was 

 widely known through his admii-able series 

 of school text-books, and was one of the 

 foremost botanists in the world. He was the 

 friend and correspondent of Darwin, and one 

 of the strongest supporters of the evolutionary 

 theory, although his views of its bearing upon 

 theological matters differed widei\- from those 

 of its originator. While Darwin was inclined 

 to an agnostic belief. Professor Gray found 

 no conflict between the doctrine of gradual 

 development, and the existence of a Supreme 

 Being. Darwin, in his letters recently pub- 

 lished, refers to Gray as one of the three or 

 four whose judgment on his theory was of 

 more value to him than that of the world 

 besides, including him with Hooker, Lyell, 

 and Huxley. From a personal acquaintance 

 with Professor Gray we can bear witness to 

 his invariable kindness and courtesy towards 

 all who had the pleasure of knowing him, and 

 he will be missed even more as the instructor 

 and friend than as the man of science whose 

 .labors accomplished so much for its advance- 

 ment. 



Scientists have long sought for a fixed and 

 invariable standard of length. The measures 

 in common use are mere arbitrary lengths, 

 and, if the original standards should be de- 

 stroyed, could not be accurately replaced. 

 The French meter is supposed to be a ten- 

 millionth part of the quadrant of the earth ; 

 but the accuracy of the original measurements 

 has been seriously called in question. The 

 so-called wave-lengths of light have been sug- 

 gested as furnishing an invariable numerical 

 magnitude ; but their excessive minuteijess, and 

 the difHculty of accurately measuring them, 

 have heretofore been an insuperable objection 



to their use. Messrs. Michelson and Morley 

 have now devised a method of measuring these 

 wave-lengths, which they claim is probablj' 

 accurate to one ten-millionth part. When it is 

 considered that a wave-length of sodium (yel- 

 low) light is only about one forty thou- 

 sandth of an inch, the delicacy of this method 

 becomes apparent. Whatever theory may be 

 held as to the nature of light, the numerical 

 values called for convenience "wave-lengths " 

 are actual and invariable magnitudes of some- 

 thing ; and if the new method of measurement 

 proves reliable, there will be no difficulty in 

 obtaining a fixed standard of length which can 

 be reproduced at any time or place. 



From certain observations upon the solar 

 spectrum, Mr. H. Crew finds that the period 

 of rotation of the equatorial region of the sun 

 is 25.88 days, corresponding to a velocitj' of 

 .024 mile a second. 



The recent total eclipse of the moon was a 

 spectacle of rare beautj-, and occurred under 

 exceptionally favorable conditions. At Boston 

 the moon was about half obscured on rising ; 

 and the gradual extension of the earth's 

 shadow over the disk, and its reappearance in 

 its accustomed brightness, were observed in a 

 sky entirely free from clouds, and through the 

 clear, pure atmosphere of a winter evening. 

 Advantage was taken of the eclipse by astron- 

 omers to determine the time of the occul- 

 tation of certain small stars by the moon, 

 which would have been invisible in the ordi- 

 nary brightness of its light ; but, aside from 

 this, the eclipse was of little actual scientific 



importance. 



——» — 



Some German chemists are said to have 

 produced artificially in the laboratory a sub- 

 stance closely allied chemically to glucose, or 

 grape-sugar, and possessing many of its well- 

 known phj-sical qualities of sweetness, etc. 

 While from a scientific point of view the 

 synthesis of such a complex compound is of 

 the highest importance, it is practicall3' of no 

 consequence whatever, as the cost of a sugar 

 formed by anj' such process must necessarily 

 be far above that of the product made in the 

 well-known way, by the action of acid upon 

 starch. 



A PAPER by Professor Gruenwald, recently 

 published in the Chemical News, upon the 

 spectra of hydrogen, oxygen, and aqueous 

 vapor, is an extremely important one, and, if 

 his theory is fully confirmed, may revolutionize 

 our ideas of the constitution of matter. It 

 would be impossible to do full justice to the 

 paper without entirely reprinting it; but it 

 may be briefly said that Gruenwald claims to 

 have discovered, from the spectra of these 

 gases and vapors, that hydrogen is a com- 

 pound of one volume of a primary substance, 

 b, with four volumes of another primary 

 substance, a, and is therefore a compound 

 substance, analogous to ammonium (NH), 

 the volume of which, on its dissociation at a 



sufficiently elevated temperature, is in the pro- 

 portion of 2 to 3. The substance a is the 

 lightest of all gaseous bodies, — much lighter 

 than hydrogen ; and &, if we regard o as a 

 univalent element, is a pentavalent gaseous 

 element similar to nitrogen. He has also 

 found oxygen, carbon, and nitrogen to be 

 compounds of simpler substances. The ele- 

 ment 6, noted above, corresponds with the 

 assumed element occurring in the sun, and 

 known as "helium;" thus proving that hy- 

 drogen is disassociated in the sun's atmos- 

 phere. Another unknown substance present 

 in the sun's corona which gives the spectral 

 line 1474, he concludes, is due to the other 

 constituent of hydrogen, a. Much more 

 extended observations will be necessarj^ to 

 prove the correctness of this alleged discov- 

 erj- ; but the facts brought forward by the 

 author are sufficiently confirmatory to justify 

 the most thorough investigation of the matter. 



Some time ago a reader of the News wrote 

 to the " Questions and Answers" column 

 desiring to know the difference between a ther- 

 mometer and a barometer. As similar inquiries 

 are not uncommon, the lack of scientittc knowl- 

 edge thus displayed was not especially noticed 

 by us. It happened, however, that at a meet- 

 ing in this city of a literary club, consisting 

 of over a dozen members, the same question 

 was recently brought up, and not a single per- 

 son could answer it. All the members were 

 highly educated, in both public and private 

 schools and academies, and yet not one of them 

 had had sufficient elementary instruction in 

 science to enable him to understand the con- 

 struction of these two simple and familiar 

 instruments. It would certainly seem as if 

 the courses of study in our educational institu- 

 tions were in need of revision. 



The efficiency and value of our schools do 

 not seem to increase with the introduction 

 of the complicated and expensive " modern 

 methods of instruction. ' ' We have an unlimited 

 number of superintendents and supervisors, 

 innumerable written and oral examinations and 

 reviews, a "seven account" arrangement of 

 " marking " for recitations, and a curriculum 

 which embraces every branch of knowledge of 

 which the human mind has ever conceived ; 

 and yet on graduation, the amount of actual 

 knowledge possessed by the pupils is phenome- 

 nally small. Our public-school system is fast 

 approximating to the same condition as that 

 of the government of the Sandwich Islands, 

 which a witty writer describes as " the works 

 of the Great Eastern in a sardine box." We 

 have a most complete and thorough " sys- 

 tem," but it is fast overshadowing the schools 

 themselves. 



PREHISTORIC MONUMENTS IN THE 

 PYRENEES. 



In a recent number of La Nature M. Julien 

 Sacaze gives a very interesting account of 

 some prehistoric monuments on the Mount 

 d'Espiaux in the French Pyrenees, recently 



