288 



THE POPULAR SCIENCE MONTHLY. 



tuted for botany ; and that Section I consist 

 of physiology vvith experimental pathology 

 and experimental psychology. 



The results of certain experiments con- 

 cerning the effect of various foniis of dis- 

 traction upon memory, reported by W. G. 

 Smith to the British Association, show that 

 the memory is most efficient when the sub- 

 ject is allowed to learn various combinations 

 of the alphabet without distraction of any 

 kind. But the power of recollection is less- 

 ened to some extent by regular movements of 

 the forefinger made by the subject while he 

 is learning; still more by the simultaneous 

 articulation of an unintelligible syllable ; and 

 most of all by the performance of simple 

 addition during the experiments. 



The committee of the British Association 

 on an International Standard for the Analysis 

 of Iron and Steel has reported, through Prof. 

 W. C. Roberts Austin, that the composition 

 of the remaining, before undetermined st.ind- 

 ard, No. 5, has now been determined by four 

 different analysts, and is accurately ascer- 

 tained. The standards will shortly be de- 

 posited with the Board of Trade, when the 

 work of the committee will have been com- 

 pleted. 



A MUSEUM of journals at Aix-la-Chapelle, 

 Germany, founded in 1886 by M. Oscar For- 

 kenbeck, is said to contain already five hun- 

 dred thousand journals in all languages. The 

 founder devoted his whole fortune for forty 

 years to the acquisition of rare and curious 

 specimens, and to subscriptions to journals in 

 all parts of the globe. He received and read 

 every day a considerable number of papers in 

 thirty different languages. Having started 

 the museum with ten thousand full collec- 

 tions, he addressed a circular letter to the 

 press of the globe asking co-operation in his 

 enterprise, and a large number of journals 

 responded favorably. 



In certain experiments made by him, Mr. 

 L. Cobbett found that tissues which had once 

 been the seat of erysipelas retained the 

 power of reacting more energetically than 

 normal tissues when inoculated with the 

 sterilized products of cultures of the erysipe- 

 las organism. He suggested that immunity 

 might be explained as being due to an ability 

 on the part of the tissues to react to chemical 

 substances produced by bacteria. 



Sir John Murray reports that the study 

 of the weather at Ben Nevis and Trieste has 

 led to the isolation of two types of weather 

 namely, perfectly clear days and those on 

 which some fog exists. The two types cor- 

 respond to quite different characters in the 

 houi'ly variation of temperature and pres- 

 sure. 



An extraordinary migration of " Croton 

 bugs" was described by L. 0. Howard in the 

 American Association as witnessed by him in 

 Washington one very dark day last summer. 



The migrating army, composed of many thou- 

 sands of individuals, consisted almost entire- 

 ly of female roaches carrying egg-sacks. An 

 investigation of the circumstances led him to 

 the conclusion that the observation indicated 

 a development of the true migratory instinct, 

 and that while the old residence of the in- 

 sects might have supported its then occu- 

 pants, provision for the sustenance of the 

 young, as yet unborn, necessitated a journey 

 in search of new quarters. The migration of 

 this army upon a dark day suggested that it 

 is by similar expeditions after nightfall that 

 new houses become infested with roaches. 



Aluminum has the property, when used 

 as a pencil, of leaving an indelible mark on 

 glass or any other substance having a siliceous 

 base. A deposition of the metal takes place, 

 and, while this may be removed by a suit- 

 able acid wash, the mark itself can not be 

 removed by rubbing or washing. Magne- 

 sium, zinc, and cadmium have a similar 

 property, but the mark of magnesium is 

 easily removed, the application of zinc re- 

 quires a wheel, and zinc and cadmium tar- 

 nish ; while aluminum is permanent and re- 

 mains bright. This property is susceptible of 

 a variety of practical applications in decorat- 

 ing glass. 



In his address before the Section of 

 Geology of the British Association Mr. L. 

 Fletcher suggested the importance to a highly 

 civilized country of having within its own 

 borders men who would make themselves 

 familiar with all that was being done and 

 had been done in the subject, would do what 

 was possible to fill up the gaps in the science, 

 and would make the results available for 

 those who had not the opportunity to make so 

 complete and original a survey for themselves. 

 He recommended that by some means each 

 university should be enabled to endow a pro- 

 fessorship of mineralogy in such a way as to 

 attract the most capable men to the study of 

 the subject ; and he pointed to the example 

 lately set by Cambridge, which encouraged 

 the students of physics, chemistry, and 

 geology to acquire a knowledge of mineral- 

 ogy and crystallography, and gave them 

 credit for that knowledge in the examination 

 for a degree. 



As a result of elaborate investigations, 

 Dr. J. S. Haldane has come to the conclusion 

 that in colliery explosions the deaths from 

 suffocation are due, not, as is generally sup- 

 posed, to carbonic-acid gas, but to the pre- 

 pondei-ance of nitrogen and the deficiency of 

 oxygen. Life could be saved if the colliers 

 could be supplied with oxygen for an hour 

 or so ; and the author has devised an appa- 

 ratus for enabling a man to breathe oxygen, 

 of which sixty litres are compressed into a 

 half-litre bottle, with tube and regulating 

 taps, supplemented by a wire compress for 

 the nose to prevent breathing through that 

 organ. 



