324 



NA TURE 



[August 6, 1896 



sugar. The question arises, Why do not all yeasts fer- 

 ment the same sugars ? If the origin of the fermenting 

 molecules is in all cases the same, has a change of en- 

 vironment power to alter them, provided many genera- 

 tions of yeast-cells are exposed to the same conditions? 

 In order to answer this question, Fischer and Thierfelder 

 attempted to breed a yeast which should ferment a sugar 

 its ancestors were incapable of attacking. Starting with 

 a yeast which could attack only dextro-glucose, they 

 mixed this sugar with Us own weight of a left-handed 

 sugar (1-mannosc), and gradually increased the propor- 

 tion of the latter during three months — a time sufficient 

 for many generations of yeast-cells to succeed one 

 another. When the proportion of glucose was reduced 

 to one-half per cent, the fermentation still went on, but, 

 on reducing it to nothing, fermentation ceased altogether. 



So far, then, this attempt has been a failure. In 

 another direction, however, the research was developed 

 with more success. The experiments described had been 

 complicated by the presence of an unknown factor — the 

 life of the fermenting organisms, .\nalogous experiments 

 were therefore made with lifeless ferments, or enzymes, 

 such as invertin, and emulsion, by allowing them to 

 attack molecules differing only in the space-relations of 

 their atoms. It was found that their power of discrimina- 

 tion was no less exact than that of the living cell. The 

 difference between a glucose- and a galactose-grouping 

 (I. and III. p. 323), which is merely a matter of H and 

 OH changing places, is for them a difference absolutely 

 vital. In the one case they attack the molecule, in the 

 other they will have nothing to do with it. The explana- 

 tion is similar to that given in the case of the sugars. 

 Invertin and emulsin much resemble proteids, and no 

 doubt possess asymmetric molecules. Their limited 

 action on the glucosides is therefore to be accounted for 

 by the supposition that the approximation of the mole- 

 cules necessary for chemical action is possible only for 

 molecules of similar geometrical build. To use Fischer's 

 simile, ferment and fermented substance must fit like 

 lock and key. For stereochemistry this image is the 

 more valuable now that the observations have been re 

 moved from the biological to the purely chemical field of 

 the lifeless ferments. And indeed for physiological 

 chemistry, also, this last step is no less important, since 

 very many of the processes which go on in the organism 

 are effected by lifeless ferments, and must be largely 

 influenced by the geometry of the molecule. 



Nevertheless, those who already deplore the use of 

 materialistic aids to the scientific imagination will find, in 

 this image of the lock and key, but another count in their 

 indictment of stereochemistry. 



Arnold Eilo.\rt, 



NOTES. 



A Reuter telegram reports that the English tourist steamer 

 Garonne arrived at \'ads6 on August 2, and landed some of the 

 members of the British expedition to observe the forthcoming 

 eclipse of the sun. They proceeded at once to the south of the 

 Varanger Fjord, where Her Majesty's cruiser I'olage had already 

 landed the a.strononiical instruments required for the obser- 

 vations. The steamship Norse King also arrived at Vadsci 

 on Sunday with a large party of astronomers to observe the 

 eclipse. 



The prospects of astronomers who have gone to Norway to 

 (jbserve the forthcoming total eclipse of the sun, are decidedly 

 good. A telegram has just reached us stating that Mr. Norman 

 Lockyer, assisted by officers and men of H.M.S. Volage, has 

 established a camp on Kio Island, and completed the arrange- 

 ments for obser\ing the eclipse. As many as forty observers 

 willbeemployed at ihisstaticm in recording various characteristics 

 NO. 1397, VOL. 54] 



of eclipse phenomena. There is every probability that fine weather 

 will prevail on the day of the eclipse at the station selected. 



Canada is not only to be the meeting-ground of the British 

 Association next year, but also of the British Medical Associa- 

 tion. At the annual meeting of the latter Association, held ir» 

 Carlisle last week, it was decided to accept the invitation to 

 meet at Montreal next year, at the end of August or beginning 

 of September. The British Association meets at Toronto on 

 August 18, so that it will be possible for the medical members 

 of it to attend both meetings if they wish to do so. 



Dr. a. Bai.dacci has undertaken, during the present year> 

 a botanical investigation of Northern Epirus, especially the 

 district of Konitza. 



The annual meeting of the Italian Botanical Society will be 

 held this year at Pisa, from September 10 to 17. The proceed- 

 ings will commence with an evening reception, and several 

 botanical excursions are arranged during the week. 



We regret to announce the death of Sir William Grove, at 

 the age of eighty-five. His investigations in phy.sical science, 

 and especially the voltaic battery which bears his name, earned 

 for him a wide reputation. He was elected a Fellow of the 

 Royal Society so far back as 1840. 



A METEOR of great size is reported to have fallen on July 24, 

 at the mines of Santos Reyes in the State of Chihuahua, Mexico. 

 A loud explosion was heard, and a mass of luminous matter was 

 seen to fall, striking the side of a mountain, and bringing down 

 with it in its course a large amount of rock. The meteor finally 

 buried itself in the ground to a great depth. 



An important astronomical exiiedition left Chicago a few 

 days ago for Flagstaft', Arizona, and ultimately for Mexico. Mr. 

 Percival Lowell heads the expedition, and will make observa- 

 tions of Mars, assisted by Mr. A. E. Douglas. Dr. T. J. See, 

 assisted by W. A. Coggeshall and D. A. Drew, will study 

 double stars, and m.ake a survey of the .southern heavens. Mr. 

 Alvan G. Clark accompanies the expedition, to put up the 24- 

 inch telescope which has been taken. 



Reuter's correspondent at Tromsci reports that the Conway 

 expedition has successfully accomplished the first crossing of 

 .Spitzbergen from west to east and back. .Starting from their 

 headquarters at Advent Bay, on the south side of Ice Fjord, the 

 party ascended the Sassendal, at the head of Sassen Bay, and, 

 branching oft' into a long lateral valley, climbed to the high 

 land, which was found to be one vast glacier reaching nearly to 

 Agardh Bay, on the Stor Fjord, or Wybe Jans Water, on the 

 east side of the island. 



The retirement of Prof. Victor Horsley from the chair of 

 Pathology in University College, London, has been made the 

 occasion of presenting him with a testimonial in the form of a 

 piece of plate and an album, as a mark of appreciation of the 

 way in which he has advanced experimental pathology in this 

 country. The album contains photographs of about fifty of the 

 subscribers to the testimonial, together with a record of the 

 work done by them, either in conjunction with Prof. Horsley or 

 in the Brown Institution, and in the Pathological Department 

 of University College, during the time he directed these 

 laboratories. 



As already announced in these columns, the Committee 

 organised by the Kazan Physico-Mathematical Society to obtain 

 funds to found a memorial of the renowned Russian geometrician, 

 N. J. Lobatchefsky, received the total sum of 9072 roubles 

 (/1433) in support of that object. A circular received from 

 Prof \assilief informs us that the fund has been utilised in the 

 following manner. A capital sum of six thou.sand roubles has 



