Catalytic Phcenomena with Allotropy. 451 



that at which ioclate of potash, when alone, decomposes into 

 iodide of potassium and oxygen, or that at which free iodine de- 

 composes with potash into iodide of potassium and oxygen. 



Now if the breaking up of iodate of potash into iodine, oxygen 

 and ^potash, is really occasioned by a change of condition which 

 the O of iodic acid suffers under the influence of peroxide of 

 manganese, &c. ; if there are many other cases of the decompo- 

 sition of compounds containing O, and if it be further the fact 

 that organic substances also, as such, can exert an allotropic 

 action upon common oxygen by inducing a series of chemical 

 changes in other organic substances, it might also appear pro- 

 bable that yeast acts alloti-opically upon one or the other consti- 

 tuent of sugar, or so as to produce a change of condition. 



Assuming that such an influence were really exerted, sugar 

 could just as little retain its original chemical condition as iodate 

 of potash could, after its had experienced the deozonizing 

 influence of peroxide of manganese, &c. The original chemical 

 relations of the constituents of sugar to each other would be 

 changed, and a new mode of combination would be produced. 



We know for certain that two of the elements of sugar — 

 cai'bon and oxygen — ai'c capable of allotropy ; and with respect 

 to hydrogen, it may also exist in various conditions, as is indeed 

 assumed by some chemists. But if it has been shown that the 

 elements which form essential constituents of organic substances 

 are capable of allotropy in an isolated condition ; if, furthex", it 

 cannot be doubted that one and the same element can exist, even 

 in combination, in various allotropic conditions ; and if there are 

 many reasons for the assumption that not only heat, light and 

 electricity, but also ponderable agents, act allotropically in cer- 

 tain free as well as chemically combined elements, we cannot 

 avoid the conclusion that a great number of chemical x'eactions 

 depend upon allotropic modificatioas of the elements, and espe- 

 cially that that class of phseuomcna might take place in organic 

 substances, from the fact that their essential constituents can 

 assume allotropic conditions. 



In what form the elements exist in chemical compounds is at 

 present a com])kte secret to us, and the processes which take place 

 in analysis and : ynthesis with I'cspect to these changes of con- 

 dition, are still entirely unknown. 



It is indeed pretty generally assumed, that it is an essential 

 part of the nature of a chemical element to remain entirely un- 

 changed in its smallest particles ; and therefore it is assumed that 

 in all chemical combinations and decompositions the elements 

 remain entirely unchanged, and that the chemical process is 

 purely niechanicul, and generally depends on the definite manner 

 m which the atoms of various elements group themselves, which 



