November io, 1898] 



NA TURE 



substance unaccompanied by its enantiomorph. The possibility 

 of such an occurrence has been pointed out by Profs Karl 

 Pearson and Fitzgerald, and is of course open to no doubt. 

 Indeed, to use Dr. Japp's own simile, it must be conceded that 

 if the type were jumbled an infinite number of times, it would 

 lead not only once but an infinite number of times also to the 

 text of Hamlet being set up ! In the matter of the synthesis of 

 asymmetric molecules throughout the past history of the earth 

 we are, it is true, not dealing with an infinite number of events, 

 but still with a number of an extremely high order, and in the 

 course of this enormously long series of events such an excep- 

 tional occurrence as the exclusive production of a considerable 

 aggregation of similarly asymmetric molecules may have talcen 

 place. This Prof. Japp himself appears to recognise, but he 

 does not admit that such an aggregation of asymmetric mole- 

 cules can by "breeding" add to the number of asymmetric 

 molecules which are unaccompanied by their enantiomorphs, 

 and he has disposed of the vague suggestions of such breeding 

 advanced by his critics. He appears to me, however, to have 

 overlooked one possible way in which such breeding can occur. 

 If we take an asymmetric molecule containing for simplicity a 

 single asymmetric carbon atom, and by purely chemical synthesis 

 generate a second asymmetric carbon atom in the molecule, the 

 new carbon atom may, as we know from the researches of Emil 

 Fischer, always have the same asymmetry, to the exclusion of 

 its enantiomorphous arrangement. But these asymmetric mole- 

 cules containing two asymmetric carbon atoms might by purely 

 chemical processes be broken down so that each yielded two 

 molecules containing an asymmetric carbon atom apiece. Each 

 of these two resulting molecules with their single asymmetric 

 carbon atom would now be ready to go through a similar cycle 

 of changes which would result in four molecules, each contain- 

 ing a single asymmetric carbon atom, and so on. In this 

 manner an indefinitely large number of asymmetric molecules, 

 unaccompanied by their enantiomorphs, might be bred from a 

 single one without the interference of any asymmetric agency, 

 living or otherwise, 



It appears to me also quite possible that the asymmetry of 

 solar radiation may originally have determined the exclusive 

 synthesis of one enantiomorph, and that the latter was in some 

 way or other utilised in the evolution of the first organism, by 

 which then this particular enantiomorphism was further trans- 

 mitted indefinitely. This is an entirely different idea from that 

 which led Pasteur to try his celebrated but abortive experiments 

 on plants in the hope that by reversing the asymmetry of the 

 sun he would obtain the vegetable asymmetric products of the 

 reverse sign to that- which they normally possess. When 

 Pasteur became a biologist as well as a chemist, he rapidly 

 realised that the asymmetric influences present in the germ of 

 life itself far outweigh the asymmetric influence of solar radi- 

 ation in determining the formation of one enantiomorph to the 

 exclusion of its fellow. It has indeed always appeared to me 

 highly remarkable that Pasteur should have embarked on these 

 particular experiments at all, inasmuch as the negative answer 

 to his inquiry is already given by nature ; for, as Prof. Japp 

 points out, the asymmetry of solar radiation in the northern is 

 the reverse of that in the southern hemisphere, whilst the 

 asymmetric vegetable products in both hemispheres are identical 

 and not enantiomorphous. Percy F. Frankland. 



Mason University College, Birmingham, October 31. 



The November Meteors. 



Prof. |. Couch Adams, in his classical investigation into the 

 dynamics of the great Leonid swarm, employed Gauss's method 

 in determining the perturbations of the surrounding planets 

 upon these meteors. Gauss's method furnishes the average 

 amount of each perturbation, and although this was sufficient 

 for the immediate object which Prof. Adams had in view, 

 it has appeared desirable to penetrate more deeply into the 

 problem. 



With this end in view the actual perturbations during the 

 33J years of the present revolution are being computed under ' 

 the direction of Dr. Downing, F. R.S., the Superintendent of 

 the Nautical Almanac, the calculations being made for meteors 

 occupying a definite position in the stream, viz. that through 

 which the earth passed in iS56. This computation will be 

 completed within the next few days ; and as the result, so far 



NO. 15 15, VOL. 59] 



as the motion of the node is concerned, can be made the basis 

 of an attempt to forecast the times of the greater showers^one 

 of which may possibly present itself next week — it seems 

 desirable that this use shall be made of the work which is 

 being done. 



The greater Leonid showers are occasioned by the earth 

 passing through the stream of ortho-Leonids, i.e. those 

 numerous Leonids which revolve round the sun in nearly 

 identical elliptic orbits. There are other Leonids moving in 

 orbits that sensibly dift'er from the ortho-orbit, and these may be 

 called clino- Leonids. Some of the clino-Leonids encounter 

 the earth in rather scattered formation every year, but the 

 ortho- Leonids are a dense procession of meteors advancing 

 along nearly coincident paths and occupying only a portion of 

 the orbit at any one time. 



It is just possible that the front of this procession may extend 

 far enough forward for the earth to encounter it this year, and 

 we are almost certain to pass through the streain in the Novem- 

 bers of next year and of one or two of the following years. On 

 each such occasion the earth receives a downpour of meteors 

 which lasts for so few hours that those observers only who are 

 fortunate enough to be on the advancing side of the earth can 

 witness the marvellous display. 



If there is one of these greater showers this year ; if the 

 meteors that shall constitute it traverse the same orbit as did 

 those that the earth encountered in 1S66 ; and if the advance of 

 the node since 1S66 were the same as that assigned by Gauss's 

 method : then would the middle of the shower of this year 

 occur at the time 



1S9S November I4d. 5h. 



But the com])utation which is being made under Dr. Downing's 

 direction shows unmistakably that the last of these conditions 

 has not been fulfilled, that on the contrary the perturbations 

 during this revolution, especially those arising from Jupiter and 

 Saturn, have been far above the average. 



Now all the calculations which have been made refer to 

 meteors situated at what we may call Station A in the pro- 

 cession, by which is meant that part of the stream through which 

 the earth passed in 1866. This part of the stream will not return 

 to the node — the point of intersection between the meteoric orbit 

 and the earth's orbit — till the end of January 1900. Accordingly 

 Station B, which the earth will encounter this year, is situated 

 in the procession about a year and a quarter in advance of 

 Station A. 



The relative positions of the disturbing planets and the meteors 

 inake it almost certain that meteors B have suffered perturbations 

 during the current revolution, which sensibly differ from those 

 affecting meteors A ; but the difference is probably not very 

 large. Again, they may have started along slightly different 

 orbits. And, thirdly, Adams's orbit can only be relied on as 

 approximate, since it is based on an insufficient determination 

 of the radiant. 



On these accounts there is risk of error in applying to meteors 

 B, the results obtained in the case of meteors A. 



With these reservations we may venture to make the correc- 

 tion ; and accordingly it is intended as soon as the computer's 

 work is sufficiently advanced, to send to the daily papers (since 

 Nature will be published too late) an announcement of the 

 amount of the correction found in the case of meteors A. It 

 will probably correspond to an epoch, several hours, possibly 

 more than a whole day, later than that calculated on the average 

 shift of the node. 



If when the correction is published it is applied to the date 

 given above, viz. to 1S9S November I4d. 5h. (5 o'clock in the 

 afternoon of Monday the 14th instant), it will furnish the best 

 attempt which the data at our disposal seem to permit, to 

 assign the time of the great shower if such an event occurs 

 this year. It will be understood that this can only be offered 

 as a prediction with the important reservations enumerated 

 above. 



Everything as yet known seems to betoken that the true time 

 win prove to be many hours later than 5 o'clock on Monday 

 afternoon, so that if one of the great meteoric showers reaches 

 the earth this year it may perhaps happen on Monday night after 

 half-past ten, or on Tuesday night after the same hour, in either 

 of which events it will be visible from all stations on this side of 

 the earth where the sky is not clouded. 



G. Johnstone Stoney. 



8 Upper Iloinsey Rise, N., November 6. 



