June 23, 1910] 



NA TURE 



505 



. -?ic experiment of Michelson on the apparent fixity of 



aether of the earth in its motion was explained by 



■ntz, though by the violent assumption that motion 



,ges the dimensions of bodies, and that the local time 



moving observer is different from that of an observer 



est. From this comes Einstein's principle of relativity, 



ch profoundly modifies our ideas of space and time, and 



- many radicals to abandon the aether. 



!ie aether drift, Prof. Augustus Trowbridge. Prof, 



Abridge spoke very briefly upon the general question 



„. relative motion of matter and the aether-nest to point 



out that, in spite of the experimental work of various 



investigators, we are still in doubt as to whether the earth 



in its motion through aether-filled space entrains the aether 



in its motion or not. Next, he explained in what respect 



the experimental method adopted by Prof. Mendenhall and 



himself differed from that of former investigators so as 



to be free from the objections which have rendered the 



previous work inconclusive. 



The effects of temperature on fluorescence and phosphor- 

 escence. Prof. E. L. Nichols. A summary of observations 

 on the fluorescence and phosphorescence from temperature 

 of liquid air to ordinary temperatures, showing that the 

 theory of Lenard is inadequate to correlate all the facts. 



Infra-red and ultra-violet landscapes. Prof. R. W. Wood. 

 Photographs taken with infra-red and ultra-violet, using 

 appropriate absorption screens, show greatly altered con- 

 trasts. Thus some substances which are white when 

 viewed by ordinary light appear black when photographed 

 with ultra-violet light. By such photographs it may be 

 possible to obtain additional details concerning the surface 

 markings of the moon and planets. 



The cause of epidemic infantile paralysis, Dr. S. Flexner. 

 A report on the experimental study of piliomyelitis in 

 monkeys, which has yielded a large number, of important 

 facts relating to the spontaneous disease in man. The 

 nature of the virus has been discovered, many of its proper- 

 ties have been ascertained, some of its immunity effects 

 have been established, the clinical and pathological 

 peculiarities of the disease have been elucidated, and a 

 basis has been secured on which to develop measures of 

 prevention. — 



Dermal bones of Paramylodon from the asphaltum 

 -its of Rancho La Brea, near Los Angeles, California, 

 J. Sinclair. This paper describes the mode of occur- 

 ...:•, shape, and microscopic structure of the skin bones 

 of an edentate animal from the Los Angeles asphaltum 

 beds. These bones, which are small, pebble-like elements 

 in the skin, resemble closely similar bones occurring in 

 a piece of skin found in a cave at Last Hope Inlet, Pata- 

 gonia. They are also known to occur in Mylodon, a 

 genus of ground sloths formerly living in North and South 

 America. As the structure of the skin bones in Mylodon 

 is quite different from what it is in Grypotherium, the 

 form from the Last Hope Inlet locality, it was a matter 

 of interest to find out to which of these genera the speci- 

 mens from the asphalt showed the closer resemblance.- 

 Thin sections of the bones were cut, and these prove that 

 Paramylodon from the asphaltum beds is almost identical, 

 in the structure of the skin bones, with Grypotherium, a 

 contemporary of early man in Patagonia. 



k note on Antarctic geology. Prof. W. M. Davis. It 

 is well known that fossil plants have been found in various 

 formations in the Arctic and Antarctic regions, indicating 

 the former prevalence there of a much milder climate than 

 that of to-day. Our prepossession naturally favours the 

 present polar climate as having been the ordinary or 

 normal polar climate of all geological time ; but inasmuch 

 as milder climates have sometimes occurred, it is eminently 

 possible that they, and not the present rigorous climate, 

 mav have been the usual polar climate through the geo- 

 logical ages. Hence a peculiar interest attaches to studies 

 of the minute structures of stratified formations, particu- 

 larly of such as are of continental origin, for from such 

 studies it may well be possible to determine climatic con- 

 ditions even in the absence of fossils. 



Some recent results in connection with the absorption 

 spectra of solutions, Prof. H. C. Jones. The absorption 

 spectra of dissolved substances are not simply a function 

 of the nature of the substances, but also of the nature of 

 th*^ solvents. When a salt like uranyl chloride is dissolved 

 11 \vaf°- we have one spectrum in water. ?-">*J\er in • 

 NO. 2 12 I, VOJ R';] 



alcohol, still another in acetone, and a spectrum in 

 glycerol which is very different from any of the above. 

 The only way in w^hich we can account for these results 

 is in terms of the solvate theory. The different solvents 

 combine with the dissolved substance and form solvates 

 having very different compositions. These affect the 

 resonance of the vibrators that are the cause of light 

 absorption differently, and, consequently, the absorp- 

 tion in the different solvents is different. The second 

 point upon which stress is laid has to do with the action 

 of one acid on the salt of another acid. In terms of 

 prevailing chemical theories, when a salt of one acid is 

 treated with a small amount of another acid, a part of 

 the salt is transformed into the salt of the second acid. 

 With the addition of more and more of the free acid, more 

 and more of the initial salt would pass over into the salt 

 of the second acid. In such solutions we should expect to 

 have the bands of both salts occurring simultaneously, with 

 varying intensity, depending upon- the amounts of the two 

 salts present. The fact is that when a salt is treated with 

 a free acid we have neither the bands corresponding to 

 the initial nor the final salt present, but bands occupying 

 positions intermediate between those of the two salts, and 

 these bands can be made to occupy any intermediate posi- 

 tion by suitably varying the amount of the free acid relative 

 to the salt. This shows that between the initial salt and 

 the one finally formed there is a series of intermediate 

 compounds or systems corresponding to the various posi- 

 tions of the bands. The number of reactions showing the 

 above relations is not small, and this raises the question 

 whether chemical reactions in general are not much more 

 complex than is usually represented by our chemical equa- 

 tions, which deal only with the initial and final stages. 



Suppression and extension of spore-formation in Piper 

 betel, Prof. D. S. Johnson. The interesting feature of 

 the structure of the flower in this plant is the presence of 

 male flowers, female flowers, and flowers bearing the 

 organs of both sexes, on. three separate kinds of spikes; 

 but flowers of each sex often bear some rudiments of 

 organs of the other sex. This shows that while some 

 flowers are apparently of one sex only, they really possess, 

 in some degree, the power to develop the organs of the 

 opposite sex. In other words, the cells from which the 

 flowers arise are capable of forming the organs of both 

 sexes, and the fact that one sex only is formed is prob- 

 ably due to some influence, internal or external, affecting 

 the cells at the time that the flowers are being initiated. 

 Experimental work on certain plants has shown that a 

 change in the light or soil supplied to apparently unisexual 

 individuals may cause the organs of the other sex also to 

 appear. This seems clear evidence that both sexes may 

 really be present in all apparently unisexual plants, but 

 that sometimes one, sometimes the other, of these is sup- 

 pressed or fails to become evident. The only plants of 

 which this seemingly cannot be true are those well-known 

 unisexual plants like the sago palm, cottonwoods and 

 willows, in which each individual bears only male flowers 

 or only female flowers year after year throughout the life 

 of the plant. Another case is that of one of the mosses, 

 in which it has been shown by Noll that the sex remains 

 constant for thirty generations when male or female plants 

 are propagated by budding. 



Solar activity and terrestrial magnetic disturbances. Dr. 

 L. A. Bauer. A recent examination of the times of 

 beginning of magnetic disturbances, as recorded at 

 observatories over the entire globe, showed that, without 

 doubt, magnetic storms do not begin at absolutely the 

 same instant of time, as heretofore believed. Instead, they 

 progress around the earth, the times generally increasing 

 as we go around the earth eastwardly ; for the quick and 

 abrupt disturbances, which are usually comparatively 

 minute in their effect on the compass needle, the complete 

 passage around the earth required from three to four 

 minutes. For the bigger effects, or for the greater mag- 

 netic storms, the rate of progression is slower, so that it 

 would take them half an hour or more to get around the 

 earth completely. There is thus introduced a new point 

 of view in the investigation of the origin of magnetic 

 storms. In addition to negatively charged electrified 

 particles coming from the sun, to which recent theories 

 sought to attribute our magnetic storms, but which the 

 author found would produce effects not in harmony with 



