128 



THE POPULAR SCIENCE MONTHLY. 



an equal volume of sulphuric acid of the 

 density of 1.53, the color ought not to be- 

 come darker, but lighter. A petroleum 

 that satisfies all these conditions, and pos- 

 sesses the proper flashing-point, may be re- 

 garded as pure and safe. 



The Paris Academy of Sciences has 

 elected Mr. Darwin a corresponding mem- 

 ber of the Zoological Section, and P;-of. 

 Asa Gray a corresponding member of the 

 Section of Botany. 



We have received from Dr. G. E. Black- 

 ham, of Dunkirk, a report of what was done 

 at the American Microscopical Congress, 

 which met at Indianapolis in August. There 

 were present about fifty microscopists from 

 different parts of the United States, and Dr. 

 R. H. Ward, of Troy, New York, was chosen 

 president. The congress was in session for 

 four days, August 14th, 15th, 16th, and l^th, 

 and one of its results was the organization 

 of a permanent association, " The American 

 Society of Microscopists." A large number 

 of papers were read, among which may be 

 named the following : " On the Limits of 

 Accuracy in Measurement with the Micro- 

 scope," by Prof. W. A. Rogers ; " A Stand- 

 ard Micrometer," by Prof. R. Hitchcock; 

 " Progress of Microscopic Ruling," by Prof. 

 J. E. Smith ; and " Construction of Ocu- 

 lars," by W. H. Seaman. The society will 

 meet next year at Buffalo. 



Prof. Hughes entertains the hope, or 

 rather thinks it possible, that we shall one 

 day be able to " tap the brain of its 

 thought" by means of the microphone! 

 He holds that all thought is accompanied 

 by an unconscious action of the articulating 

 organs, and that therefore it may come to 

 pass that by a highly-sensitive microphone 

 the articulate vibrations of the head will be 

 made audible. Of course, the theory that 

 unconscious articulation always accompa- 

 nies thought is purely hypothetical ; but in 

 these times it is best not to pronounce any- 

 thing impossible unless it clearly implies a 

 contradiction in terms — an absurdity. 



Experiments made by Messrs. Corenwin- 

 der and Contamine show that the amount of 

 sugar in beet-roots is in direct ratio to the 

 superficial area of their leaves. They fur- 

 ther show that in the leaves the sugar oc- 

 curs mainly in the midrib, and that it there 

 exists in the state of glucose mingled with 

 a small quantity of crystallizable sugar. 

 In the secondary veins and in the paren- 

 chyma the proportion of sugar is far less 

 considei'able. 



The London Academy is authority for 

 the statement that Mr. Grenville Murray's 

 recent work, " Round about France," has 

 been seized in France by the authorities. 



Du. Weyl points out in the ChemiscJie 

 Industrie the defects of the usual methods 

 of determining the heat-value of fuels, and 

 recommends, as preferable, decomposition 

 of the fuel by dry distillation and analytical 

 determination of the solid, liquid, and gase- 

 ous products of decomposition. The water, 

 tar, and gas that are formed are measured 

 and their heat of combustion ascertained 

 with the aid of data that have been supplied 

 by Favre and Silbermann and Deville. The 

 final result will, of course, exceed the true 

 combustion-value of the coal by the amount 

 of heat equivalent to the work of decom- 

 position into coke, tar, and gas. The decom- 

 position of the coal should be done as quick- 

 ly as possible, and at a high temperature. 



The French journal La Science pour Tous 

 reckons the annual importation of ivory into 

 England at 650,000 kilogrammes, of %hich 

 about one half is there employed in the arts, 

 and the other half reexported. The cutlery- 

 works of Sheffield alone consume 200,000 

 kilogrammes per year. Tusks vary in weight 

 from 450 grammes to 74 kilogrammes. To 

 supply the ivory annually taken to England, 

 50,000 elephants must be killed. But 

 though, perhaps, most of the tusks go to 

 England, very many are exported directly 

 to other countries and consumed at home. 



A PROCESS for treating hop-stems so as 

 to produce from them textile fibres is thus 

 described in the Polytechnic Journal : First, 

 the stems are boiled in water with soda or 

 soap, then washed again, and once more 

 boiled in dilute acetic acid. They are then 

 washed and dried, and when propei'ly 

 combed can be worked like other textile 

 materials. The fibres are said very closely 

 to resemble those of flax, and to excel in 

 elasticity, softness, and dui-ability. 



A WRITER in the London Times asserts 

 that, by the practice of shoeing horses, we 

 diminish the sureness of the animal's feet, 

 and foster all kinds of splints and other 

 diseases. He maintains that any horse, even 

 one accustomed to shoes, would very soon 

 go more easily in every way on our hardest 

 roads, and with far less liability to slipping 

 and disease, unshod, than he now does when 

 shod with iron. All that is necessary is to 

 " keep the edges of the hoof slightly rounded 

 off with a rasp, to prevent the raveling-up 

 of the edges." 



Senor Moreno, employed by the Gov- 

 ernment of Buenos Ayres to explore Pata- 

 gonia, has discovered a new volcano, that 

 of Chalten, in the Patagonian Andes, in lati- 

 tude 49° 8' south, longitude 73° 10' west. 

 It is a magnificent peak, rising high above 

 the surrounding mountains, and the natives 

 report that it is almost always sending forth 

 smoke and cinders. . 



