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SCIENTIFIC NEWS. 



[April 20, iS 



of ^aper$, Hectare?, etc* 



ROYAL INSTITUTION. 

 On March 22nd the Rev. Dr. Dallinger delivered his third 

 and last lecture on the " Least and Simplest Forms of 

 Life." The lecturer, referring to the enormous rapidity with 

 which the generations of these micro-organisms multiply, 

 said that they had seemed to him likely to serve as 

 useful subjects for investigating the effects of a slow pro- 

 gressive change of environment upon organisms. In 

 this idea he was encouraged by letters which he received 

 from Charles Darwin. Some remarkable results had 

 been previously obtained by subjecting Entomostraca to 

 a water becoming very slowly more and more impreg- 

 nated with common salt. In this manner such creatures 

 have been modified not merely into distinct species, but 

 even into a new genus. On considering the agent most 

 suited to the resources of a private biological laboratory, 

 he pitched upon heat, and accordingly he exposed water 

 rich in putrescent matter and swarming with microbia, 

 such as had been described in the former lectures, to a 

 very gradual increase of temperature, beginning with 

 60° — 70° Fahr., which seems to be the point at which 

 these creatures multiply most rapidly. An apparatus 

 was devised and arranged by means of which jars con- 

 taining the liquid and its inhabitants could be kept auto- 

 matically within \ degree Fahr. of any desired tempera- 

 ture for any length of time, but could, if required, be 

 made gradually warmer. The stage of the microscope 

 was so arranged that drops of liquid taken out for ex- 

 amination could be kept at the same temperature as that 

 in the jars. 



The experiments proved very tedious and delicate. 

 Sometimes weeks had to be spent in raising the 

 temperature a single degree, but by care and patience 

 numbers of the species under observation were brought 

 not merely to live, but to prosper and multiply, at 158° 

 Fahr. The effects of increasing heat were not regularly 

 progressive. There occurred critical points at which 

 multitudes perished and the remainder became languid. 

 But on allowing the heat to remain stationary for a time, 

 the survivors recovered, multiplied as before, and did 

 not seem in the least incommoded by a rise of a few 

 degrees more. Then came another critical point, which 

 had to be tided over with the same precautions. 



No permanent structural change was recognised, but a 

 decided physiological modification had evidently been 

 effected, since if a few of the microbia which were 

 brisk and lively at 158^ Fahr. were dropped into water 

 at 6o£ — 70°, their initial temperature, they were 

 instantly killed. In the same manner if any microbia were 

 taken from water at 6o2 — 70'', and plunged into water 

 at 1582 Fahr., they perished at once. 



Dr. Dallinger's experiments were brought to a pre- 

 mature close by an accident to his apparatus, but he 

 hopes to resume them with improved apparatus. 



ROYAL SCOTTISH SOCIETY OF ARTS. 

 Among the reports submitted by a Committee on papers 

 previously communicated on April 9th, was one with re- 

 ference to Mr. Hart Robinson's writing telegraph. For 

 the first time, it was stated, in the history of telegraphy, 

 a sender was enabled by the means of this invention 

 (which has already been described) to transmit to a dis- 



tant station a message in handwriting, the facsimile of 

 what was sent, with nearly the same speed as that of 

 ordinary writing. This writing telegraph marked a new 

 departure in the history of practical telegraphy. 



Mr. D. A. Cormack read a paper on the " Protection 

 of Propellers from Corrosion," in which he advocated 

 the use of his " Vindex " as a safe, sure, and cheap pro- 

 tector. The invention, it appeared, is founded upon the 

 knowledge of the different degrees of affinity of oxygen 

 for various metals, and for the same metal in different 

 degrees when its parts differ in their chemical components. 

 When immersed in a favourable medium, these act and 

 react upon each other in such a way as to cause rapid 

 deterioration in the electro-positive portions. Brass being 

 negative to the iron and steel in shafts and propellers, the 

 latter rapidly corrode unless provided with some electro- 

 positive absorbent in contact with themselves. This was 

 provided in the " Vindex," which might be employed in 

 the form of nuts for blades, or of caps for tail ends. The 

 metal used was zinc, or a compound of which the basis 

 was zinc, the tenacity of which, though low, had been 

 proved, when used in the form of blade-nuts, to be fully 

 equal to the tensile strength of the stud. Further, only 

 a small proportion of the brass nuts required to be re- 

 placed with zinc. In the case of the cap over the tail nut, 

 when inconvenient to take it off in order to renew the 

 zinc, this might be done in place by means of a cover 

 provided with a gate for the reception of the liquid metal, 

 temporarily set upon the space to be filled. In cases 

 where the cast-iron cap loaded with zinc could not be 

 conveniently applied, a zinc cap might be cast, and secured 

 over the tail nut by a single bolt screwed into the end of 

 the shaft. The apparatus was shown to the meeting, and 

 the invention was favourably commented upon. 



ROYAL INSTITUTION OF BRITISH ARCHITECTS. 

 On April 9th, Mr. Vivian B. Lewes, F.I.C., F.C.S., Royal 

 Naval College, read a paper upon " Illumination and 

 Ventilation," and the author said all our existing illumi- 

 nants resemble each other in composition ; the light- 

 giving waxes, fats, oils, and gases, all depending for their 

 lighting and heating effects upon the elements carbon and 

 hydrogen, which, by a selective process of combustion, 

 emit light, at the same time producing as products of 

 their complete combustion carbonic acid gas and water 

 vapour, both of which have, when present in quantity in 

 the air we breathe, a very deleterious effect upon our 

 health. 



The unit of illuminating power as adopted in England 

 is a "sperm" candle of the size known as "sixes," 

 which, when burning under normal conditions, consumes 

 120 grains of sperm per hour, and emits an amount of 

 light known as " one candle power." Adopting this 

 standard and experimentally determining the amount of 

 material used, in the best form of lamp or burner for its 

 consumption, we have a means by which we can compare 

 the lighting power and the vitiating effect which our 

 illuminants give. 



The amount of light to be obtained from a given 

 volume of coal gas depends upon the form of burner 

 used, whilst the vitiating effect upon the air is also 

 expressed in the number of adults who would exhale the 

 same amount of carbonic acid gas during respiration. 

 The gas used for the tests was that supplied to the City, 

 which, during the past six months, has had an average 

 illuminating power known as i6'5 candles. All volumes 



