September 17, 1891] 



NATURE 



47 



One entire session of this and the Physical Section jointly 

 was devoted to an elaborate monograph by A. Macfarlane, on 

 principles of the algebra of physics. 



Section B — Physics. 



Prof. F. E. Nipher, President of Section B, opened the pro- 

 ceedings with an address on the functions and nature of the 

 ether of space. Many reasons formerly given for the existence 

 of such an ether, he said, no longer exist. For twenty-five 

 years it was taught that light is an elastic pulsation in an 

 incompressible jelly-like medium. In 1865, Maxwell proposed 

 the theory that light is an electric displacement in a plane at 

 right angles to the line of propagation. In 1888, Thomson 

 showed that the compression wave required by the elastic theory, 

 l)ut absent in fact, might be dispensed with in the theory by 

 making its velocity zero ; and that this does not involve an 

 unstable condition of the medium, and is therefore admissible. 

 The showing up of light in space occupied by matter shows that 

 the ether within must either be more dense (as Fresnel believed) 

 or less elastic than that existing in free space. It is certainly 

 very difficult to understand what there can be in the molecules 

 of matter which can increase the density of an incompressible 

 medium. The beautiful experiment of Michelson and Morley 

 shows apparently that the ether at the surface of the earth moves 

 with it. It is dragged along as if it were a vivid liquid. The 

 t^.eld of a steel magnet is, however, a rotational phenomenon. 

 It is a spin which is maintained permanently without the ex- 

 penditure of energy. It seems, therefore, that the resistance to 

 shear which shows itself in the adhesion of the ether to the 

 moving earth must be a rigidity due in some way to motion. 

 Other experiments of Michelson and Morley on the motion of 

 light in moving columns of water have been taken as proof that 

 the ether in water is condensed to nine-sixteenths of its volume 

 in air. The ether in water certainly behaves as if it were more 

 dense, but it is another matter to say that it is so. It seems im- 

 probable. It is still a mathematical fiction which covers a gap 

 in our knowledge of the ether. The speaker thought, that the 

 experiment should be repeated with water at rest within a tube 

 which should be mounted on elastic supports in a moving rail- 

 way car. The water tube and observer's seat should be rigidly 

 connected and swung on dampened spring supports from the top 

 and sides of the car. The question to be settled is whether the 

 ether or any part of it is at rest in space, and does it sweep 

 through the interior of bodies which move through it as wind 

 sweeps through the leaves and branches of a tree. This form of 

 the experiment is the one contemplated by Eisenlohr's analysis 

 leading to Fresnel's formula, and it is capable of great variations in 

 the conditions of experiment. It is, however, more difficult and 

 more expensive than the one so well executed by Michelson and 

 Morley. Whatever its results may be, it promises to add greatly 

 to our knowledge of the physics of the ether. 



Prof E. W. Morley, who has for several years been conduct- 

 ing researches under the auspices of, and with funds supplied 

 by, the Association, read papers describing his method of de- 

 termining the coefficient of expansion by means of interference 

 fringes. He is able to determine the expansion of bars of any 

 length as accurately as Fizeau did that of half-inch bars. 



C. B. Thwing read a paper on colour photography by Lipp- 

 mann's process, and exhibited samples which show a tinge of 

 colour when looked at in the right light. 



II. A. Ilazen, of the U.S. Signal Service, di.>cussed the 

 question " Do tornadoes whirl?", and gave results of elaborate 

 and careful study of tornadoes and of the debris left by them, 

 from which he concludes that the common notion of a whirl in 

 tornadoes is unfounded. 



Section C — Chemistry. 

 Prof. R. C. Kedzie, of the Agricultural College, Michigan, 

 chose the subject of alchemy for his annual address. 



Thirty-three papers were read before this Section, and the 

 meeting was characterized by the Secretary of the Section as 

 the most valuable ever held. 



Mr. Morley contributed valuable material to this Section also, 

 in regard to the synthesis of weighed quantities of water from 

 weighed quantities of oxygen and hydrogen. His determination 

 f the ratio of atomic weights is : oxygen 15 '888, hydrogen i. 

 The Committee on Spelling and Pronunciation of Chemical 

 Terms, which has been engaged in this work for several years, 

 made their final Report, which will be printed and widely dis- 

 tributed, in order to secure uniformity if possible. 



NO. II 42, VOL. 44] 



•' Biological Functions of the I,ecithines " was the title of a 

 paper by Walter Maxwell In a paper presented by Mr. Max- 

 well at the 1890 meeting of the Association, he showed that a 

 vegetable organism, during the initial stages of growth and 

 under the action of the ferments operating in germination, 

 possesses the power of taking the phosphorus present in seeds 

 or in soils, as mineral phosphates, separating the phosphorus 

 from the inorganic combination, and causing it to reappear in 

 the young plantlet in an organic form as a lecithine. In brief, 

 it was shown that the lecithine bodies are a medium through 

 which the phosphorus of the mineral kingdom passes over into 

 the vegetable kingdom. In the second part of Mr. Maxwell's 

 paper he went on to show that the lecithine bodies, on the 

 other hand, present in the animal kingdom revert to the mineral 

 form under the action of the ferments present in the animal 

 organism. The investigations were conducted with the egg of 

 a hen. The phosphorus contained in the egg, in the respective 

 forms of mineral phosphates and organic phosphorus compounds 

 as lecithines, was determined. In the next place, the eggs were 

 incubated, and the products of incubation were studied. It 

 was found that the phosphorus contained in the natural egg as a 

 lecithine reappeared in the incubation product as calcium phos- 

 phate, and forming the bone of the chicken. 



In a paper by Dr. Gustav Hinrichs, facts were adduced to 

 show that the logarithms of the molecular weights of the hydro- 

 carbons have a direct relation to the fusing and boiling points of 

 these substances. This is believed to be the instance discovered 

 where logarithms exist between changes in physical or chemical 

 condition. 



Section D — Mechanical Science and Engineering. 



The President of this Section, and ex-officio one of the Vice- 

 Presidents of the Association, is Prof Thomas Gray, of Terre 

 Haute, Ind., the inventor of a great variety of ingenious 

 apparatus, including the seismoscope and seismograph shown 

 to the Association on their excursion to Terre Haute last year. 

 His address was a carefully prepared discourse on problems in 

 mathematical science. It was technical in character, and dealt 

 with the teachings of mathematics and physics in their applica- 

 tion to engineering. 



Among the papers before this Section was one on Government 

 timber tests, by B. E. Fermor, Chief of the Bureau of Forestry. 

 He said there had been inaugurated in the forestry division 

 of the Department of Agriculture a comprehensive S2ries of 

 tests and examinations of American timbers, the ultimate object 

 of which is the solution of a biological problem— namely, to 

 es'ablish the relation of technical and physical qualities to each 

 other and to conditions of growth. In the pursuit of this in- 

 vestigation, naturally, many questions of immediate practical 

 value in the use of wood for engineering purposes will be solved. 

 The novelty in this enterprise lies mainly in its comprehensive- 

 ness and scope. A very large number of tests alone on material 

 of known origin and condition, and an exhaustive examination 

 of the same will permit generalization and the recognition of 

 laws of inter-relation. The work requires the organization of 

 four distinct departments. First, the selection of test material 

 from as many essentially diffisrent climatic and soil conditions as 

 the species may occupy, five fully-matured and two young trees 

 being carefully selected on each site and cut up for test material ; 

 secondly, the examination of the structure and physical condition 

 of the test material, requiring the minutest detail ; thirdly, the 

 usual testing with special care ; and, lastly, the compilation and 

 comparative discussion of the results of the tests in connection 

 with the physical examination and the known conditions of 

 growth. Besides more trustworthy data than hitherto attainable 

 of the qualities of our principal timbers, there is to be gained 

 from this investigation a knowledge of conditions under which 

 desirable qualities can be produced by the forest grower. 



Prof J. B, Johnson read a paper on the United States tests 

 of strength of American woods, made at the Washington Uni- 

 versity testing Laboratory, St. Louis. 



Section E — Geology and Geography. 

 Prof. J. J. Stevenson, of New York, presided. His address was 

 on the relations of the Chemung and Catskill on the eastern 

 side of the Appalachian Basin. He traced the groups along the 

 eastern outcrop from Tennessee into New York, across Southern 

 and Western Pennsylvania, and eastward through Northern 

 Pennsylvania again into New York, using the work of Prof. 

 While and Messrs. Carill and Ashburne in Pennsylvania, and 



