568 Chronicles of Science. [Oct., 



hydrogen or oxide of carbon, never emit sparks, the production of 

 the latter cannot be due to an evolution of reducing gas absorbed 

 during the fusion, but is due, according to the author, to the forma- 

 tion of oxide of iron at the moment the molten metal comes in 

 contact with air. This curious phenomenon is well known to those 

 engaged at blast furnaces. The sparks are known by the workmen 

 as "jumpers," and their presence is usually held to indicate an 

 approximation to white iron. These sparks are absent during the 

 running of grey iron from the furnace, and only begin to make their 

 appearance when the iron is about No. 4, the usual degree of grey- 

 ness preferred in South Staffordshire for puddling. The sparks are 

 best observed during the running of white iron from the furnace, 

 especially if the molten metal is not very fluid, at which times a 

 vast number are produced, particularly in the channel ; and some- 

 times after the pigs have "set," little jets of sparks are continuously 

 discharged for many minutes, which discharge is accompanied by a 

 hissing sound. M. Caron's view may probably be correct, but a 

 correspondent of the ' Chemical News,' who signs his name T. B., 

 says that he is inclined to attribute the production of these sparks 

 to the combustion of carbon and not of iron, as there is an entire 

 absence of the peculiar scintillations displayed by burning iron. 



A very striking mode of demonstration in the lecture-room that 

 burning bodies increase in weight has been contrived by H. Kolbe. 

 A glass rod is fastened in a horizontal position to one arm of a 

 balance. Upon this is fastened a glass cylinder in which a candle 

 is burnt, connected with which, by a glass tube, there is a Y-tube 

 for condensing the vapour, a flask filled with lime-water for carbonic 

 anhydride, and two more V-tubes containing soda-lime. The last 

 are connected by an india-rubber tube with a Bunsen's pump, by 

 which a steady current of air is drawn through the apparatus. The 

 beam is first counterpoised ; as the candle burns away the arm of 

 the balance to which it is attached sinks down until its progress is 

 arrested by the table. 



Mr. W. T. Suffolk, the well-known microscopist, has experi- 

 mented during a pedestrian tour on the most advantageous methods 

 of boiling water, and has come to the conclusion that the very best 

 arrangement is an "Etna" of French construction made of very 

 thin copper, electro-plated, and weighing, with a store of 6 oz. of 

 spirit, 1^ lb. The time occupied in boiling half a pint of water is 

 from seven to ten minutes, and the consumption of spirit about 

 two fluid drachms. The apparatus requires a perfectly calm atmo- 

 sphere for its proper action; this maybe secured by building a 

 small cromlech of flat stones, which are always at hand in hilly 

 countries, and with the help of a large handkerchief as a further 

 protection against the wind, no difficulty will be found in securing 



