88 Relations between- Chemical Change, [January, 



his engine working was to produce instead of absorbing heat. 

 This he attributed to induced currents in the brass ; but 

 using a glass calorimeter, the conclusion to which he came, 

 on the whole, was that it made no difference whatever in 

 the calorific .effects, whether the engine produced work or 

 not. Such are also the conclusions to which he afterwards 

 came after some years of further experiments. At any rate, 

 the only experiments he gives us in which the working of 

 the engine made any difference tend to show that the engine 

 produced not absorbed heat. We can only say, then, that the 

 whole subject is at present in a state of chaos, and that no 

 legitimate conclusion can be drawn without a new and care- 

 ful experimental examination of the whole of the facts. 



5. Let me point out next how eminently unsatisfactory are 

 the conclusions drawn from the experiments of Weber and 

 Kohlrausch. As we said before, they drew from these the 

 inference that a milligramme of hydrogen produced electricity 

 enough to attract 208 tons at a distance of 1000 metres in 

 opposition to gravity — that is, to raise anything less than 

 208 tons 1000 metres, with a constantly increasing velocity. 

 But I venture to say their experiments were wholly incon- 

 clusive. For how did they operate ? They first measured 

 the attractive force of the electricity contained in a Leyden 

 phial. They then examined what effect this had in moving 

 a magnetic needle, placed in a galvanometer. Next they 

 tried what was the quantity of water which, in its decompo- 

 sition in a circuit, corresponded with the same motion of a 

 magnetic needle. Comparing the two they drew the deduc- 

 tions I have just mentioned. But here was the fallacy. In 

 order to prevent a spark passing, and to enable the 

 electricity in the Leyden phial to move the magnetic needle, 

 they passed the current through a long column of water. 

 But they seem to have forgotten that if, instead of the 

 column of water, they had substituted a great length of 

 wire of corresponding resistance, and had formed that wire 

 into a number of galvanometers, the electricity in the Leyden 

 phial would probably have given the same amount of motion 

 to many thousands of magnetic needles, instead of to one, 

 and, consequently, that these conclusions were probably 

 wrong many thousands of times over. I ought to say that I 

 have not read the account of these experiments in the 

 original, but only the description of them given in Watts's 

 " Dictionary of Chemistry ;" so that it is possible I may have 

 misunderstood them. 



6. Other philosophers have been as much out in their 

 calculations. Regnault calculated how much was the 



