550 THE POPULAR SCIENCE MONTHLY. 



of energy, and it is only the comparatively high cost of the fuel gen- 

 erally used in these zinc which prevents them from being practically 

 useful. A galvanic battery gives out very nearly the whole energy 

 due to the chemical combinations which take place in it ; so that it is 

 hardly too much to say that, were a battery to be employed to drive 

 an electro-motor, under suitable conditions, we could obtain at least 

 sixty per cent, of the chemical energy, while the best-known steam- 

 engine will only give about ten per cent, of the chemical energy of 

 the coal and air consumed in its furnace. There is thus a large margin 

 for the first cost of the substance to be consumed in the battery. 

 Saturday Review. 



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SKETCH OF EOBEET WILHELM BUNSEN. 



IT has been given to few scientific investigators to be more closely 

 identified through their discoveries with the practical progress of 

 the world, to see the fruits of their researches taken up and applied, 

 made appreciable and beneficial in a greater diversity of lines, than to 

 Robert \YiLnELM Bunsen. 



Professor Bunsen w^as born in Gottingen, March 31, 1811. His fa- 

 ther was Professor of Theology, and of the Oriental Languages and Lit- 

 erature, in the University of Gottingen. Having passed through the 

 course of the gymnasium, he entered the university, devoted himself to 

 the study of chemistry and physics, and was graduated as a Doctor of 

 Philosophy in 1830, publishing as his inaugural dissertation, "Enu- 

 meratio ac Descriptio Hygrometorum," or, "Enumeration and De- 

 scription of Hygrometers." He afterward studied in London, Paris, 

 and Vienna, and became, in 1833, tutor at the University of Gottin- 

 gen ; in 1836 he was appointed Professor of Chemistry at the Poly- 

 technic school in Cassel ; took the corresj^onding chair at the Univer- 

 sity of Marburg in 1838, and remained there thirteen years ; then 

 went, in 1851, to Breslau, where he planned a famous working labora- 

 tory ; and in the next year went to Heidelberg, where he has for 

 thirty years added to the fame of the great university. 



His works in his chosen field have been numerous ; their value, 

 whether they are measured in relation to the advance of theoretical 

 science, or as factors in the perfection of the operations of practical 

 art, has been very great. 



In 1834, in conjunction with Berthold, he published a research 

 upon hydrated j^eroxide of iron as an antidote to arsenical poison, in- 

 troducing a remedy which, having become universally known and uni- 

 versally accessible, may be regarded as a positive addition to the secu- 

 rity of human life against a certain class of dangers. 



He next, in 1835, described some singular compounds which the 



