THE ENERGY OF THE LIVING PROTOPLASM. l6g 
In the second group of katalytic actions may be counted the 
transformation of maleic into the isomeric fumaric acid by mineral 
acids, of maleic ester into fumaric ester by contact with hydro¬ 
chloric acid at the ordinary temperature (Skraup) and of citra- 
conic into mesaconic acid ( Delisle , Franz) ; of hydromellitic into 
isohydromellitic acid by hydrochloric acid ( Bacycr ) ; of dihydro- 
terephthalic into an isomeric acid by a solution of caustic soda, 
the formation of paramidophenol from phenyl-hydroxylamine 
(E. Bamberger) and that of paranitroso-compounds from nitro- 
samines by acids. Also the transformation of oleic into elaidic 
acid by nitrous acid deserves mentioning. 
In connection with the third group we mention the following 
observations : platinum black brings about an oxidation of 
hydrogen, of alcohols, and of various other compounds ; it unites 
sulphur dioxide with dry oxygen to form sulphur trioxide ; it 
combines hydrogen with hydrocyanic acid into methylamine at 
no 0 (Debus) ; it transforms a mixture of nitric oxide and hydrogen 
into ammonia and water ; it accelerates the decomposition of 
hydroxylamine in presence of caustic potash ; it decomposes 
peroxide of hydrogen energetically ; it transforms ozone into 
common oxygen (Mulder) ; it decomposes azoimide into ammonia 
and nitrous oxide (O. Loew), and nitrososulphates into sulphates 
and nitrous oxide (Pelouze). 
Finely divided iridium or rhodium decomposes formic acid 
into carbon dioxide and hydrogen (Deville and Debray) ; palla¬ 
dium powder effects an oxidation of hypophosphorous acid with 
liberation of hydrogen ; (I) finely divided copper incites a rapid 
decomposition of formic aldehyde by caustic potash with libera¬ 
tion of hydrogen, (2) it also decomposes diazobenzene chloride into 
nitrogen and chlorbenzene at low temperatures. (3) Zinc filings 
condense at ioo° acetaldehyde to aldol and crotonaldehyde. 
All these actions of finely divided metals can be best ex¬ 
plained by the assumption that a modification of heat waves 
takes place in such a manner that this energy can now pass 
more easily into chemical energy. With platinum black this 
(1) Engel, Compt. rend, no, 7S6. The- chemical explanation given by this 
author is certainly incorrect. 
(2) O. Loew, Ber. D. Chem. Ges. 20,145. 
(3) Gattermann , ibid. 23,1218 and 25 , ioqi, footnote. 
