SCIENCE. 



615 



is a convenient substitute for that of the foot against the 

 ground. I recently had a beautiful illustration while 

 riding slowly on the horse-cars in New York. A vehicle 

 passed rapidly between me and a picket fence, every 

 stroke of its wheels against each stone of the pavement 

 being returned as a whistle from the opposite fence. The 

 acoustic effect was much like that of the trilling of a 

 canary bird. 



I cheerfully accord to Prof. Robinson the credit of giv- 

 ing mathematical expression to this truth. His observa- 

 tion is none the less original even if others have preceded 

 him, and I am by no means sure that any one has pre- 

 ceded him in giving it publication. 



W. Le Conte Stevens. 



40 W. 40th St., New York. 



Dec. lyth, 1881. 



NOTES FROM OUR FOREIGN EXCHANGES. 



Phosphorescent Fungi — At the present day, several in- 

 ferior species of fungi are known, which have the power of 

 throwing out a phosphorescent light. M. Cri6, Professor 

 of the Faculty of Sciences at Caen, has noticed new species 

 which spring up on old stumps or between the bark and the 

 wood of the elder-tree. 



Rectification of Inferior Alcohol. — Electricity is now em- 

 ployed in the rectification of inferior alcohol. The elec- 

 tricity generated by a voltaic battery and a dynamo-electric 

 machine is passed through the alcohol so as to disengage 

 the superfluous hydrogen. Bv this means, beet-root al- 

 cohol, which is usually very poor, can be made to yield 

 eighty per cent, of spirits, equal to that obtained from the 

 best malt. 



A Japanese Antelope. — Several interesting acquisitions 

 have recently been made by the Zoological Garden of Lon- 

 don. Among other rare animals, it has obtained a Jap- 

 anese antelope which has never before been in an}' collec- 

 tion in Europe. The antelope of Japan (Capricornus Cris- 

 pus) is found only in the highest mountains of the Niphon 

 and Shikoku islands. Very little is known of its habits 

 and it has been but incompletely described by Siebold in 

 his Fauna of Japan. 



Phosphorescent Ice — Mr. J. Allen has written to " Nature" 

 an interesting letter, in which he describes a curious phe- 

 nomenon of phosphorescence of floating ice, observed in the 

 Polar regions. Every time that the bow of the ship, where 

 the observer placed himself, shattered the ice during the 

 night, the ice suddenly shone with a very perceptible light. 

 It is a light similar to that which is produced on the break- 

 ing of sugar, the cleavage of sheets of mica, or the striking 

 together of pieces of flint in the dark. 



Electric Fusion of Metals — M. Siemens, in the presence of 

 the members of the Congress of Electricians, performed the 

 following curious experiment : in a crucible conveniently 

 arranged, furnished with a perforated cover, fragments of 

 steel were placed ; the two currents of an electro-motor ap- 

 paratus entered the lower and the upper part of the crucible. 

 In 14 minutes the metallic mass became hot, reddened and 

 melted. The mass showed no inflation. The expense of 

 the combustile consumed by the electric apparatus is much 

 less than that which fusion by direct application of heat 

 would necessitate. 



Electricity produced by Light. — While traveling in Mexico, 

 M. L?ur, mining engineer, was struck by the fact that the 

 amalgamation ot silver ore, by what is called the American 

 method, only operates well under the influence of light. 

 According to him, the action does not take place in the 

 darkness. He sought the cause of this unexpected effect 

 and his experiments seemed to him, to show that light, by 

 acting upon the mixture of sulphide of silver, sulphate of 

 copper, salt and mercury, develops electricity without which 

 the amalgamation cannot take place. 



M. Boussingault, however, expressed an objection to this 

 conclusion, which appears decisive; that in Mexico, the 

 operation is not confined to small quantities, but whole 

 mountains of ore are acted upon. Now light is only able to 

 act upon the periphery of the latter, and the largest part of 

 their mass remains in permanent darkness. 



The Telephone in a Storm. — A very curious experiment 

 was made and announced by M. Rene" Thury, of Geneva. 

 He stretched a metal wire from one roof to another. One 

 extremity of the wire was in connection with a telephone, 

 the opposite extremity with the earth. During a storm, 

 every time there was a lightning stroke, even at a distance 

 of 20, 30, and even 40 kilometres, the telephone gave a very 

 characteristic sound. This noise, according to M. Fleury, 

 was due to the peculiar electric currents, called currents of 

 induction, produced under the influence of the atmospheric 

 electric discharge. It was a sort of return impact. 



The Sulphate of Alumina of Commerce. — For a long time 

 there has been a tendency to substitute sulphate of alumina 

 for potash or ammonia alum, since it is richer in alumina. 

 But the manufacture of pure sulphate of alumina, that is to 

 say, free from iron, is not easy, at least in an economical 

 point of view. 



During the last twenty years, pure hydrated alumina has 

 been prepared at a low cost, and by saturating this alumina 

 by sulphuric acid, a warm liquid is obtained which congeals 

 into a dry and easily transportable mass of sulphate of 

 alumina containing about 15 per.cent. of alumina. 



The products obtained in this manner are relatively ex- 

 pensive, and it would be a great advantage to purify the 

 ferruginous sulphate of alumina furnished by the action of 

 sulphuric acid upon common clay, if this purification could 

 be accomplished by an easy and less costly method. 



Extraction of Magnesia from Sea Water. — The Moniteur des 

 produits chimiques contains the following method of abstract- 

 ing magnesia from sea water: "magnesia can be precipi- 

 tated from sea water by means of calcium, just as from 

 other more concentrated solutions. After precipitation and 

 rest for a day, a cubic metre of sea water gives a precipitate of 

 gelatinous magnesia, about 80 litres in volume. The treat- 

 ment on a large scale of water whose magnesia is to be de- 

 posited in large basins, can easily be accomplished, speak- 

 ing in an industrial point of view; the calcium will be the 

 greatest expense. 



If the magnesian sediment thus obtained is treated with 

 phosphoric acid, a precipitate of tribassic phosphate is ob- 

 tained, which, filtered, becomes an' excellent chemical 

 agent for the precipitation of ammonia from excrements in 

 the form of ainmoniac-magnesian sulphate, which is a pow- 

 erful manure. 



Spontaneous Combustion of Carbon. — Spontaneous combus- 

 tion in colliers is a veiy important question, for, in 1874, 70 

 cases of this kind occurred. The recent investigations of 

 M. Haedicke have thrown light upon this subject. These 

 experiments were conclusive in proving that this combus- 

 tion is due to the influence of iron pyrites. This substance 

 becomes oxidized when submitted to moisture and is changed 

 into ferrous sulphate. During this decomposition, the 

 carbon bursts and offers a larger surface to the action of 

 the air. The ferrous salt is then transformed into a ferric salt 

 which yields up its oxygen to the carbon. In order to pre 

 vent spontaneous ignition, all currents of air should be ex 

 eluded, unless they should be allowed to enter from the be 

 ginning in great quantities, so that the air acts as a cooling 

 agent. As moisture prevents ignition and the accumulation 

 ot oxygen, the introduction of a jet of steam, where the tem- 

 perature of the carbon has been raised to a high degree, will 

 also act as a preventive. 



Sea-sickness. — A correspondent of the " Paris Medical " 

 has sent a communication to the editor, which will prove 

 interesting to many persons who suffer sea-sickness in their 

 travels. 



" In a recent voyage from Algeria to France," he writes, 

 " the sea being very rough, and almost all the passengers 

 being sick, the officers of the ship could offer but insuffi- 

 cient means of relief. Among the passengers there was 

 one, about thirty years old, who suffered cruelly. He vom- 

 ited continually for thirty hours, and his sufferings became 

 so severe that the surgeon had to be called. After hearing 

 him prescribe lemon juice, I asked him if he had not mor- 

 phine or chloral. To my astonishment he replied that he 

 had none. I then offered him one centigram of morphine 

 and my syringe. This was accepted. A solution was made 

 in 20 drops of water, was injected into the epigastrium, and, 

 a half hour afterwards the sickness was allayed. He ceased 



