94 



NATURE 



[November 23. 1905 



exist in solution in equilibrium, in proportions which 

 depend on the conditions the ^-compound predominating. 

 Change takes place in a similar manner in other media. 



The process by which a monose is converted into a biose 

 must l» regarded as precisely similar to that by which 

 a-glucose and 0-glucose arc converted into the two methyl- 

 glucosides : the behaviour of maltose, in fact, is such as 

 to characterise it unquestionably as glucose-ct-glucoside ; 

 isomaltose is presumably the stereoisomer^ glucose-£- 

 glucoside. 



When glucose undergoes condensation "uncontrolled," 

 it should give rise to both maltose and isomaltose, the pro- 

 portions of which ultimately present in equilibrium would 

 depend on their relative stability under the conditions 

 operative at the time. Hut, inasmuch as hydrolysis under 

 the influence of enzymes is an absolutely selective process, 

 being so controlled that it lakes plate in one direction only, 

 it might be supposed that synthesis under their influence 

 would also be a controlled operation, and that the tendency 

 of the enzyme would be to reproduce the biose which it 

 hydrolyses : apparently this point of view was present in 

 Croft Hill's mind and lid him to suppose, at first, that 

 maltose was the actual product ; as a matter of fact, it is 

 uncertain at present whether maltose is produced at all : 

 it is certainly not the sole or even the predoaiinant 

 product. 



The formation under the influence of the enzyme of a 

 single biose, isomeric with that which it hydrolyses, could 

 be accounted for on the assumption that both are produced 

 initially, but that the one again undergoes hydrolysis as 

 soon as it is formed, so that it all but disappears. 



Proof is given in the present communication that when 

 the condensation is effei ted under laboratory conditions the 

 action takes place in the manner indicated above ; in other 

 words, the two products required by theory are both 

 formed. Evidence is adduced to show that isomaltose is 

 the 0-gIucoside correlative with the a-glueoside maltose. 

 Experiments are described bearing on the formation of 

 isomaltose by the agency of the a-enzyme maltase and of 

 its correlative maltose by the agency of the /8-enzyme 

 emulsin which leave little doubt thai the two bioses are 

 producible from glucose. Whilst it is left undecided 

 whether maltase can give rise to maltose, evidence is cited 

 which at least renders it probable that emulsin does not 

 give rise- to isomaltose. 



"Studies on Enzyme Action. — Lipase." By Henr) E. 

 Armstrong, F.R.S. 



The study of vegetable lipase is of special importance, 

 as the ordinary fats — which are hydrolysed under its in- 

 fluence with peculiar readiness — are not asymmetric 

 material but simply glycerides of acids of the acetic or 

 oleic series. The interest of the inquiry is enhanced by the 

 fact that animal lipase, according to Dakin, acts selec- 

 tively but the selective effect of lipase is of a different 

 order from that displayed, for example, by an enzyme of 

 the sucroclastic class, which can only attack one member 

 of a pair of enantiomorphous isomerides. 



In the course of the experiments, Connstein's contention 

 has been confirmed that the presence of acid is necessary 

 to condition the hydrolysis and that practically any acid 

 is effective provided a sufficient amount be used. Aspartic 

 and glutamic acids — which are formed at an early stage 

 of the germination of seeds — were found to be highly- 

 active; glycin and asparagin, however, were practically 

 without effei I 



All attempts resulted in failure which were made to 

 obtain an extract containing an enzyme, whether from the 

 freshlv-ground material directly or after this had been 

 deprived of the fatty matter and whether or no acid were 

 present. Apparently, acids do not act merely by liber- 

 ating the enzyme. 



The Ricinus enzyme has been found to have but little 

 action, not only on ethylic butyrate, on acetin and on 

 dimethvlic tartrate and racemate but also on ethylic 

 mandelate, which, according to Dakin, is readily attacked 

 by animal lipase. 



It is difficult to resist the impression that the differences 

 observed are not merely consequences of differences in 

 stability of the various ethereal salts but that the Ricinus 

 enzyme is possessed of properties which make it specifically 



NO. 1S82, VOL. JZ) 



capable of promoting the hydrolysis of glycerides of the 

 higher fatty acids. 



Received August 10. — " Fertility in Scottish Sheep." 

 By Dr. F. H. A. Marshall. Communicated by Prof. 

 E. A. Schafer, F.R.S. 



Received August 18. — " The Pressure of Explosions. 

 Experiments on bolid and Gaseous Explosives." Parts i. 

 and ii. By J. F. Petavel. 



Part i. deals with the methods and apparatus used in 

 the research. Part ii. is devoted to a study of the proper- 

 lies of cordite. 



Received September 7. — " On the Nature of the Galvano- 

 tropic Irritability of Roots." By Dr. Alfred J. Ewart 

 and Jessie S. Bayliss. Communicated by Francis Darwin, 

 h 1 r.Sec. R.S. 



After the contradictory experiments of Mullcr-Hett- 

 lingen, and Elfving, Briinchorst found that strong currents 

 produced a positive, and weak currents a negative, curva- 

 ture. Roots hence appeared to possess a parallelotropic 

 irritability to electrical currents, reversible according to 

 the intensity, as in the case of heliotactic and heliotropic 

 irritability. The experiments were not altogether satis- 

 factory, nor did they reveal the mode of stimulation, so 

 further investigations seemed desirable. 



1 hese have shown that the curvatures are produced by 

 the acid and alkaline products of electrolysis liberated on 

 opposite sides of the root. The acid products are more 

 effective than the alkaline, so that when the current is 

 led transversely through the subapical sensitive region 

 the curvature always takes place towards the positive 

 electrode; but if one electrode is placed upon the hvpocotyl 

 and the other on the irritable zone, the curvature is always 

 low. mis the latter electrode, whether it be positive or 

 negative. These galvanogenic curvatures are hence chemo- 

 tropie in origin, as has been shown by direct experiments 

 with acids and alkalis. Thus, if the roots are imbedded 

 at varying distances in gelatin through which a current 

 is passed, the roots curve in regular order towards the 

 electrodes shortly after the acid or alkali, as evidenced 

 by phenolphthalein, has diffus cl near to them. 



In addition, the application of the electrolysed region 

 of a root or of filter paper moistened with decincrmal acid 

 or alkali pri duces similar 1 urvatures. 



All these curvatures have been produced on a klinostat 

 and without any injury to the root. Indeed, in many cases 

 a constant current of 0000009 of an ampere is sufficient 

 1 1 1 ause a curvature. Using non-polarisable electrodes, no 

 response is given unless very sin ng currents are used, 

 Mine the stimulation is now dependent upon the restricted 

 internal polarisation in the root. 



It is doubtful w'hether the electrical currents in the soil 

 call this spei ial irritability regularly into play. The power 

 of curving towards faintly acid cr alkaline regions must 

 aid the root greatly in reaching soil where soluble con- 

 stituents are most likely to be abundant, or where 

 anaerobic nitrogenous decomposition (with a production of 

 ammonia) or the subsequent aerobic nitrification (with a 

 production of traces of nitrous and nitric acids) are in 

 progress. 



The non-development of any power of curving away 

 from strong acid cr alkali is to be explained by the non- 

 occurrence of high local concentrations in normal soil. 

 Even when a strong local acidity or alkalinity is artificially 

 produced in the soil, the roots are killed before they can 

 curve away from it, and even if the apical zone did curve 

 away, the non-curving zone behind would be rapidly killed. 



Sociological Pocietv, Octoher 24. — Sir T r hr. Corkbmn 

 in the chair. — Biological foundations of sociology : Dr. G. 

 Archdall Reid. The author outlined modern teaching on 

 the subject of heredity, accepting the Weissmannian con- 

 clusion regarding the non-inheritance of acquired 

 characters. These principles he applied to human qualities 

 with especial reference to the possibilities of selective breed- 

 ing. Four main conclusions were reached : — (a) That 

 there is a confusion, in popular and in uncritical medical 

 opinion, of variation with acquirement. Many individual 

 acquirements are considered innate, (b) That racial 



