June 15, 1888.] 



SCIENTIFIC NEWS. 



569 



0t i^aperis, Hecture^, etc* 



ROYAL SOCIETY. 

 At the meeting on May 31st a paper on the " Conditions 

 of Evolution of Gases from Homogeneous Liquids," by 

 Mr. V. H. Veley, M.A., of University College, Oxford, 

 was communicated by Mr. A. Vernon-Harcourt, F.R.S. 



This paper is particularly concerned with the for- 

 mation of gases resulting from chemical changes 

 occurring within liquids. In the course of some ex- 

 periments on the evolution of carbonic oxide, in which 

 an aqueous solution of sodium formate had been poured 

 into diluted sulphuric acid and the mixture heated to 

 35 'S'^, Mr. Harcourt noticed that certain particles of 

 silica, present as an impurity in the salt, seemed to serve 

 as nuclei for the evolution of the carbonic oxide. The 

 experiment was accordingly repeated under precisely 

 the same conditions as to mass of salt, concentration of 

 acid, temperature, except that the particles of silica were 

 carefully filtered off before the aqueous solution of the 

 salt came in contact with the acid. It was thus found 

 that a temperature of 73'' was required to obtain a rate 

 of evolution of gas equal to that of the experiment above. 

 This result led to a series of experiments on the effect 

 of chemically inert particles on the evolution of gases ; 

 it was found invariably that their presence increased to 

 a very remarkable degree the rate of formation of gas, 

 whether evolved from aqueous solutions or from salts in 

 a state of fusion. 



The phenomenon is apparently comparable to the 

 eftict produced by the addition of fine particles to a 

 supersaturated solution of gases in water, such as ordi- 

 nary soda-water. The two cases are however different ; 

 in the one case the gas is preformed and dissolved, in 

 the other the gas is in process of formation, and in most 

 instances is not apparently dissolved in the liquid. 



It v,?as observed in most cases that, conditions of 

 temperature remaining the same, the gas is evolved at 

 first slowly, then is gradually accelerated until it reaches 

 a maximum, at which it remains constant for some time, 

 and then diminishes at a rale proportional to the dimi- 

 nution of mass. The phenomenon of initial acceleration 

 is apparently common to many cases of chemical change. 



Effect of Pressure. — A sudden increase of pressure 

 from a fraction to the whole of an atmosphere decreases, 

 or even completely stops, the evolution of a gas from a 

 liquid in which it is being formed ; the phenomenon 

 of initial acceleration then repeats itself. Conversely, a 

 decrease of pressure produces a sudden increase in the 

 evolution of gas. These effects are only temporary ; 

 there is apparently no permanent difference between the 

 rates at a reduced and at ordinary pressures. 



In the last portion of the paper the decomposition of 

 formic acid into carbonic oxide and water is considered, con- 

 dition other than temperature and masses of reacting sub- 

 stances being kept constant. The curve representing the 

 course of the change in terms of mass of formic acid is 

 shown to be hyperbolic, i.e., the rate of change is thus 

 proportional to the square of the mass of formic acid. 



A note by Dr. Beevor and Professor Horsley, F.R.S., 

 " On Some of the Motor Functions of Certain Cranial 

 Nerves, and of the Three First Cervical Nerves in the 

 Monkey ' (ISIacacus sinicits), was especially devoted to 

 proving the proposition that the levator muscle of the soft 



palate is inserted not by the facial (the seventh) nerve as 

 usually supposed, but by the eleventh, the accessory to 

 the vagus. 



Sir William Turner, F.R.S. , communicated a second 

 memoir on the structure of the placenta in the lemurs, 

 the species which he had examined on this occasion 

 being [Lcimir .xanthornysta.x), the specimen having been 

 sent to him by F. E. Beddaw, Esq., Prosector to the 

 Zoological Society. The investigation which he had 

 made supported the conclusions arrived at in his first 

 memoir, viz., that in the lemurs the placenta is diffused 

 over the greater part of the surface of the chorion, and 

 that the uterine mucous membrane is not shed along 

 with it. As the lemurs also possess a large sac of the 

 allantois, they are in' their placental characters as far 

 removed from man and apes as it is possible for them 

 to be. Hence the author concludes that they ought not 

 to be included in the same order with the apes, but 

 should form a special order of mammals to be called 

 either with Milne Edward's Lcmuria, or with Victor 

 Caras' Prosimii. 



ROYAL INSTITUTION. 

 The Friday evening lecture on June ist was delivered 

 by Professor Ewing. The lecturer pointed out that 

 seismology was a science with two sides, one geological, 

 the other mechanical. The geologist attacked the subject 

 by at once attempting to refer earthquakes to their 

 source in the crumbling, tearing, or slipping of strata, in 

 volcanic eruption, in the collapse or explosion of sub- 

 terranean cavities. The mechanical student of earth- 

 quakes, on the other hand, concerned himself with the 

 character of the motion that was experienced, and with 

 the means by which an earthquake spread from point to 

 point by the elastic vibration of rock and soil. His first 

 business was to find out exactly how the ground moved 

 during an earthquake, to determine by direct measure- 

 ment the amount and direction of every successive 

 displacement, and the velocity and rate of acceleration at 

 every instant while the shaking went on. This was the 

 problem of seismometry, and the lecture would deal with 

 the solution of this problem, and with some of the results 

 which had been obtained in the measurement of earth- 

 quakes in Japan. Earthquakes happened there with a 

 frequency sufiRcient to satisfy the most exacting seismolo- 

 gist. It had been estimated that one or another part of 

 the empire was shaken every day, and in Tokio, where the 

 measurements had been made, there was an earthquake, 

 on the average, about once a week. Most early attempts 

 to reduce the observing of earthquakes to an exact science 

 had failed, because they were based on a wrong notion 

 of what an earthquake was. It had been imagined that an 

 earthquake consisted of a single isolated jerk, or of a few 

 jerks, easily distinguishable from any minor oscillations 

 that might accompany them. The old column seismometer, 

 for instance, attempted to measure what was called the 

 intensity of the shock by means of a number of columns 

 of various diameters which stood like ninepins on a level 

 base. It was expected that the shock would overthrow 

 the narrower columns up to a breadth which would gauge 

 the intensity of the disturbance, and also that the line in 

 which they fell would show the horizontal direction of 

 transit of the earthquake wave. In fact, however, such 

 columns fell most capriciously when they fell at all. The 

 reason was that in an earthquake there was no single out- 

 standing impulse, but a confused jumble of oscillations, 

 very numerous and very irregular, which shifted their 



