1871J Electricity. 115 



100 kilos, of the ice artificially made by another process has been found to melt 

 in six days under the same conditions. The secret of this appears to reside 

 in the high degree of compactness and freedom from fissures in the ice pro- 

 duced by M. Toselli's machine. 



A short time ago, a fire broke out at the premises of MM. Behague and 

 Paxer, wholesale silk mercers ; the fire was, however, very quickly discovered, 

 and this gave rise to the discovery that it originated inside a large parcel of 

 black-dyed silk which had been returned from the dye-house only 24 hours 

 previously. That black-dyed silk is somewhat liable to spontaneous com- 

 bustion has been a well-known fact for years, but, notwithstanding the 

 researches of Persoz and others on this subject, the real cause is not quite 

 elucidated. 



In some researches on J" The Simultaneous Boiling of Two Liquids which 

 are not Miscible," M. A. Kundt gives an account of a series of experiments 

 made with water and benzol, water and oil of cloves, water and sulphide of 

 carbon. The chief point of interest in his results is that two liquids, not 

 miscible with each other when in contact, boil at a lower temperature thah 

 when the most volatile of these liquids is brought to ebullition by itself. 



Mr. M. G. Farmer, of Boston, has fused the native iridosmine by placing the 

 natural grains in a groove in charcoal, and subjecting them to the action of a 

 current of voltaic electricity from sixty large Bunsen cells, using large platinum 

 wires to make contact with the ends of the groove. He obtained in this 

 manner bars of perfectly compact metal, brittle and very hard. The operation 

 was anything but pleasant, on account of the intense light emitted and the 

 fumes of osmic acid, which attacked the eyes and nostrils, producing the phe- 

 nomena of rose or hay fever, and sunburning the face. Mr. Farmer estimates 

 the temperature of the fusion at about io,ooo° F. The object of the experi- 

 ment was to prepare a bar of the alloy for the purpose of electric illumination. 

 On rendering it luminous by an electric current, he found that when near the 

 melting-point one square inch of surface evolved light equal to 2800 candles, 

 which threw shadows in broad daylight at noon, and produced excellent photo- 

 graphs. The same battery converted solid bichloride of iridium into fused 

 metal as soft and ductile as platinum. 



Messrs. Mottershead and Co. have just brought out an improved automatic 

 regulator, maintaining constant temperatures in laboratory operations, which 

 is applicable to any operation in which gas is used as a source of heat. When 

 fitted to copper drying closets or air-baths the temperature may be limited to 

 any degree from 75 F. upwards. This apparatus acting automatically, the 

 temperature is unaffected by varying pressure of gas, the common source of 

 accident in ordinary drying closets. Drying closets and evaporating basins 

 are also fitted on a slightly modified plan, in which a reservoir of air placed 

 inside the oven is made to act on the regulator, thus avoiding the necessity of 

 a double copper chamber, and at the same time forming a sufficiently sensitive 

 apparatus for many practical purposes. 



ELECTRICITY. 



Dr. J. G. Fischer has described some curious effects caused by lightning 

 striking his house, a detached residence situated near Hamburg; the lightning 

 first struck and demolished a stack of chimneys, and next found its way to the 

 soil along a zinc pipe for conveying the rain-water from the roof downwards ; 

 the pipe alluded to, previously sound, was perforated in three places in a very 

 curious manner ; at one of the holes the metal was forced outward, while at 

 the two other holes the metal had been forced inward in such a manner as to 

 close the tube for the passage of water, at the point where the tube reached at 

 the bottom the earthenware drain-pipe ; the latter was smashed, the soil which 

 covered it having been scooped out ; no fire ensued by the striking of the 

 lightning, nor was fusion of metal anywhere perceptible. 



The substitution of aluminium for platinum in Grove's batteries has been 

 successfully tried by Mr. Nettleton. Two small cells, the size of the aluminium, 



