Royal Society. 63 



by a remarkable weakening of affinity. In this case, on the con- 

 trary, we find an elevation of temperature of the greatest intensity 

 and shortest duration, producing a state directly the reverse, 

 which is marked by an increased affinity. That this state is 

 produced only by the highest temperatures, and yet that when 

 once produced, it disappears again by heating to a temperature 

 even below 392° F., is not less remarkable, although explicable. 

 The conversion of allotropic into common phosphorus does not 

 take place instantaneously, but in a longer period of time. In 

 the same manner, oxygen which has become allotropic by the 

 high temperature of the electric spark may by rapid cooling pass 

 through the interval between that temperature and 392° F. 

 without going back completely to the ordinary state, if the dura- 

 tion of the cooling be shorter than the time necessary for it to 

 return to the usual modification in that interval of temperature. 

 From this it will be understood, how so small a fraction of the 

 oxygen is obtained in this permanent state of allotropy, and how 

 this state so readily disappears at a temperature above 392° F. 

 It is highly probable, that the temperature at which ozone 

 is decomposed into water and oxygen, and that at which 

 allotropic oxygen is converted into the ordinary form of that 

 substance, are not the same. 



I hope to return again to this subject. During the preceding 

 investigation, which was carried on in the laboratory of Heidel- 

 berg, I enjoyed the benefit of the good advice of Professor 

 Bun sen, for which I have to express to him my warmest thanks. 



VIII. Proceedings of Learned Societies. 



ROYAL SOCIETY. 

 [Continued from vol. v. p. 468.] 

 March 17, fTHHE following papers were read : — 



1853. A 1. " On Animal and Vegetable Fibre as originally 

 composed of Twin Spiral Filaments, in whicli every other structure 

 has its Origin ; a Note showing the confirmation by Agardh, in 1852, 

 of observations recorded in the Philosophical Transactions for 1842." 

 By Martin Barry, M.D., F.R.S., F.R.S.E. 



After referring to the drawings to his paper on Fibre, published in 

 the Philosophical Transactions for 1842, and the opinions entertained 

 by physiologists regarding the peculiar views he advanced in that 

 paper with reference to the original composition of organic fibre, 

 the author states that, after the lapse of eleven years, these views 

 have been fully confirmed, and in proof of this refers to a paper — 

 "De cellula vegetabili fibrillis tenuissimis contexta" (Lundse, 1852), 

 by Agardh. He further remarks, that his paper of 1842 contains a 

 record of other observations made in a field beyond the region of 

 Agardh's researches ; observations which he thinks explain how it is 



