SCIENCE- GOSSIP. 



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sudden changes that characterise the nitrogen 

 compounds. Indeed, it appears to me that the 

 slow, continuous changes of the former are far 

 more analogous to the chemical changes that take 

 place within the living organism than the awful 

 swiftness and violence of the changes that accom- 

 pany the molecular transformations of the latter. 

 It would be well to remember that the majority of 

 the so-called "nitrogen" compounds have an equal 

 right to be regarded as carbon compounds, for in 

 most cases they arise from the substitution of 

 nitrogen atoms in a carbon compound. Their 

 excessive unstability may be due to a very large 

 extent to the fact that the carbon is not quite 

 capable of controlling the motion of the nitrogen 

 atom, and which, therefore, is always liable to 

 " run amock " among the other atoms of the com- 

 pound. 



Dr. Allen maintains "we have yet to find a class 

 of silicon compounds which would behave like 

 carbon compounds in the storing of energy. 

 Silicon seems to perform a passive, not a dynamic 

 function in the life of this world." Applied to 

 ordinary temperatures this statement is undoubtedly 

 correct, but applied to a temperature at which the 

 compounds of silica are fluid, this ceases to be so. 

 Silicon, even to a greater degree than carbon, 

 possesses an affinity for oxygen. This is especially 

 exemplified in the enormous number of oxy- 

 compounds to which silicon gives rise. 



The difference between the compounds of 

 carbon and the compounds of silicon is mainly 

 a difference in temperature. Nothing appears more 

 probable than at such a temperature that the in- 

 ternal cohesion of the siliceous bodies is reduced 

 to the same degree that at ordinary temperatures 

 characterises the carbon compounds, that silicon 

 would possess energy-storing properties to an even 

 greater degree than carbon ; but the storage of 

 energy by the silicon would not be brought about 

 by the addition of hydrogen, as appears to be the 

 case with carbon, in ordinary life. Some other 

 element, perhaps oxygen itself, would perform this 

 function in life at the temperature I am con- 

 sidering. 



The idea that carbon gradually displaced the 

 silicon in living matter with the falling tempera- 

 ture appears to offer a satisfactory explanation of 

 the otherwise unaccountable presence of silica in 

 all living matter. Indeed, it will be noticed that 

 the earlier and more rudimentary forms of life 

 often contain a comparatively large amount of 

 silica ; for example, the sponges. In still earlier 

 types of life, now long since extinct, silica appeared 

 to play an even more important part than it does at 

 present. To give one example, there is used for 

 polishing purposes, under the name " Tripoli," a 

 collection of siliceous skeletons of the lowest 

 microscopical infusoria, which are sometimes found 

 in considerable layers in the form of a sandy mass. 

 The microscopic remains of the infusoria have a 



pointed, though not angular shape, and it is for 

 this reason they can be used for polishing without 

 scratching. 



On Dr. Allen's theory no explanation can be 

 given of the existence of such siliceous forms of 

 life. The presence of silica in living matter bears 

 witness to the slow process of evolution, much in 

 the same way that the gills on the neck of 

 the embryonic babe bear witness to an aqueous 

 origin. 



Dr. Allen doubts whether the temperature of the 

 world's surface was ever sensibly higher than it is 

 at present. Equally doubtful is the hypothetical 

 meteoric origin of the earth. The nebular theory 

 of cosmic origin, in spite of certain mathematical 

 difficulties, is a far more probable theory than that 

 supported by Dr. Allen. Indeed, we have in Jupiter 

 and the other giant planets of the solar system actual 

 examples of planetary bodies so hot as to be in a 

 fluid state, and this in spite of their immense 

 gravitational force. As Jupiter now is, so may the 

 earth have been. This world, being of much 

 smaller mass, would cool far more rapidly than 

 Jupiter. The spectroscope, too, teaches us divers 

 facts concerning the evolution of the heavenly 

 bodies. It shows how there exist in space vast 

 masses of incandescent gas — nebula?. Further, it 

 indicates that there are suns white-hot, suns yellow- 

 hot, suns red-hot, and suns but barely visible and 

 fast cooling down into everlasting night. Such 

 facts as these must be taken into account in 

 framing any hypothesis concerning the making of 

 worlds. 



My critic's argument that the earth's crust does 

 not bear any geological evidence of ever having 

 been at a sensibly higher temperature than at 

 present cannot be taken seriously. For a great 

 space of time the temperature of the earth's surface 

 has undoubtedly not been very greatly different 

 from that which now reigns, and this accounts for 

 the complexity of life as it at present exists upon 

 the earth. This space of time, however, bears no 

 more ratio to the time I am considering than 

 does a drop of rain in a thunderstorm bear to the 

 total number of falling drops. The forces of dis- 

 integration would have long since swept out any 

 traces of such a period. 



In conclusion, I might state that I am but 

 appealing to the universal law of evolution, the 

 law that appears to run throughout all Nature. 



The conception that life originated in a sea of 

 white-hot fluid is immensely superior, from a purely 

 chemical point of view, to that advocated by Dr. 

 Allen. Under such conditions all the elements 

 could freely intermingle together, and life could 

 thus take form, substance, and nutriment out of 

 the complex mixture that such a fluid must have 

 been. The original elements that composed early 

 living matter could not, however, have been those of 

 which it is now formed. 



13 Hampton Road, Bristol, May '21, 1900. 



