Feb. 14, 1889] 



NA TURE 



371 



showing exceptionally strong CH bands, were "by a 

 London maker." Prof. Smyth once admitted (though with 

 great reserve), wit'i " the English spectroscopists," that the 

 CO spectrum might be that of pure carbon ; he " begs now 

 to apologize for that error ; " and, long after he has come 

 off victorious throughout the whole line, the rumble of 

 distant thunder is heard in his " concluding notes." 



Mr. John Aitken's investigations regarding the formation 

 of small clear spaces in dusty air are already known to 

 the scientific public, from the abstract published in 

 Naturk, vol. .xxix. p. 322 (January 1884). His paper 

 on dew, a short abstract of which appeared in Naturk, 

 vol. xxxiii. p. 256 (January 1886), is also contained in 

 the Transactions. Some observations in addition to those 

 indicated in Naturk are described. These refer to eva- 

 poration from extremely dry soils in Britain and France, 

 and also, on the evidence of travellers, in Australia and 

 South Africa. Additional evidence regarding the formation 

 of the dewdrop is also given. 



Mr. A. Crichton Mitchell has repeated Forbes's and 

 Tait's experiments on the thermal conductivity of iron, 

 copper, and German silver. His observations were con- 

 ducted under improved experimental conditions, and the 

 methods of calculation were different in some respects. 

 These differences are pointed out and explained by Prof. 

 Tait in an introduction to Mr. Mitchell's paper. On the 

 whole, Mr. Mitchell's work confirms that of previous 

 experimenters. One of the most important of his 

 conclusions is that iron forms no exception to the rule 

 that the thermal conductivity of ordinary metals increases 

 with rise of temperature. 



Prof. C. G. Knott, of Tokio University, Japan, gives a 

 full experimental investigation of the thermo-electric 

 peculiarities and the electrical resistance of hydrogenized 

 palladium. In another paper he treats of the electrical 

 resistance of nickel at high temperatures, and concludes 

 from his results that " there is a strong presumption that 

 the Thomson effect in metals has a close connection with 

 the mutual relations of resistance and temperature." 



From a series of observations made in atmospheric 

 electricity at the top of Dodabetta, the highest hill in the 

 Neilgherries, Prof. C. Michie Smith is led to the conclusion 

 that on the edge of a dissolving mist the potential is 

 lower than the normal, while in a condensing mist it is 

 higher than the normal. He says : " If my results are 

 confirmed by more extended observations, strong support 

 will be given to the theory which looks on the condensa- 

 tion of a number of slightly charged particles into larger 

 drops as the cause of the high potential indicated by 

 disruptive discharges." In connection with this, results 

 -obtained by Mr. H. N. Dickson regarding the direction 

 of earth-currents at Ben Nevis are worthy of note. When 

 mist descends on the mountain, or rain (or snow) falls, a 

 down current is observed in the telegraph cable when 

 put to earth at both ends : but when the mist rises from 

 the mountain-top the direction of the earth-current is 

 upwards. 



Von Helmholtz contributes an account of galvanic 

 currents passing through a very thin stratum of an 

 electrolyte. 



Many of the facts brought out in a series of papers by 

 Dr. H. R. Mill and others on various physical and chemical 

 conditions of tidal estuaries should be of much use because 

 of their evident bearing on the distribution of various 

 forms of animal life, and on questions connected with 

 meteorology. 



A number of years ago Prof. Tait undertook the work 

 of determining the pressure-errors of the Challen^^cr ther- 

 mometers. This investigtion gave rise to many others : 

 such as the lowering of the maximum density-point of j 

 water by pressure ; the variation of the compressibility 

 of water with temperature, pressure, and amount of salt 

 dissolved ; and the question of the internal pressure in 

 water. The various results obtained by Prof. Tait are 



contained in a series of notes scattered throughout the 

 Proceedings. 



The complete series of observations made at the Ben 

 Nevis Observatory have been handed over to the Royal 

 Society of Edinburgh for publication ; and, from time to 

 time, valuable meteorological information in connectioi 

 with the Observatory is communicated to the Society and 

 appears in their Proceedings. Dr. Murray remarks that 

 " the refusal of assistance (to the Observatory) by the 

 London Committees may be partly due to the fact that there 

 are many claims on the funds which they administer, but 

 it appears also to be very largely due to a want of proper 

 knowledge of what has been done, and what may be 

 reasonably expected to be done, by the Observatory, there 

 being no Observatory in these islands that can compete 

 with the Ben Nevis Observatory for the accuracy and in- 

 trinsic value of the hourly observations ; and absolutely 

 no pair of stations anywhere in the world that can be 

 named alongside the Observatory and the station at 

 Fort William as contributing data in furtherance of 

 our knowledge of storms and the science of weather 

 generally." 



These volumes contain two or three papers in the de- 

 partment of engineering. Mr. A. C. Elliot gives a new 

 formula for the pressure of earth against a retaining wall, 

 which is an improvement on Rankine's formula. In a 

 paper on "Cases of Instability in Open Structures," Dr. 

 E. Sang discusses a class of theorems of which one 

 previously enunciated by him— to the effect that any 

 symmetric structure built on a rectangular basis, having 

 no redundant parts, and depending on longitudinal 

 strain alone, is necessarily un5table~was a p.irticular 

 example. 



In the department of chemistry we note an elaborate 

 paper by Prof. Dittmar and Mr. John Mc.Arthur, entitled 

 " Critical Experiments on the Chloro-platinate Method 

 for the Determination of Potassium, Rubidium, and An>- 

 monium ; and a Redetermination of the Atomic Weight of 

 Platinum." The paper consists of five parts— uvo detailing 

 experiments on the composition of chloro-platinate of 

 potassium, a part on Finkener's and Tatlock's methods 

 of potash determination, a part descriptive of experiments 

 on chloro-platinate of rubidium, and another describing 

 experiments on chloro-platinate of ammonium. The 

 authors conclude that the atomic weight of platinum is 

 very nearly I95"5. 



Prof. Dittmar also gives, in conjuction with Mr. C. 



A. Favvsitt, a " Contribution to our Knowledge of the 

 Physical Properties of Methyl-alcohol." The "vapour- 

 tension " (why nox. pressure since it is pressure.') is in- 

 vestigated under varying conditions, and the specific 

 gravity of aqueous methyl-aldohol for all the integral 

 percentages is also tabulated at o" C. and 1 5 "56 C. 



Dr. John Waddell has determined the atomic weight of 

 tungsten by an entirely new method, and has obtained 

 results confirmatory of the commonly accepted value. 



Comparatively few papers dealing with botanical ques- 

 tions were communicated to the Society during the period 

 under consideration. A note "On the Structure of the 

 Pitcher in the Seedling of Nepenthes, as compared with 

 that in the Adult Plant," in which the late Prof. Alexander 

 Dickson first called attention to the peculiar large mar- 

 ginal glands of Nepenthes, is of much interest. The 

 Proceedings contain the fourth part of " Diagnoses 

 Plantarum Novarum Phanerogamarum Socotrensium, 

 &c.," by Prof. Bayley Balfour, and a note "On De- 

 generated Specimens of Tidipa sylvestris, by Mrs. A. 



B. Griffiths. Mr. John Rattray contributes a note on 

 the marine plant Ectocarpus. 



The number of papers in zoology and allied sciences is 

 somewhat large. 



In the summer of 1868, HM.S. Lightnini^ explored the 

 region of the North Atlantic lying between the Hebrides 

 and the Faroes. In 1869 H.M.S. Porcupine made three 



