April 21, 1892] 



NATURE 



593 



formula ; the fundamental equations remain everywhere the 

 same. In other words, the question is one of the theory of all 

 conditions whereby heterogeneous substances or heterogeneous 

 phases of the same substance have assumed, after reciprocal 

 influence, a condition of equilibrium independent of the time. 



The general theory of these conditions has been developed by 

 J. Willard Gibbs sixteen years ago ; a German edition of this 

 magnificent and incredibly many-sided investigation is at present 

 in the press. Through van 't Hoff and Arrhenius we are placed 

 in a position to insert m the equations of this man of science, which 

 contain necessarily a great number of yet unknown functions, the 

 expressions for these functions, together with the numerical 

 constants, and to thus solve the problem numerically from case 

 to case. 



It must, however, be borne in mind that the functions in 

 question, expressing as the sum of its single forms the total 

 energy of the system considered, are yet known only for the 

 cases of gases and dilute solutions, i.e. for the cases where the 

 inner energy has become independent of the volume. As far as 

 the knowledge of the equation of condition reaches, extends 

 the possibility of mastering the heterogeneous conditions and 

 chemical equilibria. And we see at this place hov/ the different 

 parts of general chemistry reach to one another the hand ; the 

 solution of the problems which were mentioned in the first part 

 of this address is also, for that just discussed, the unavoidable 

 condition of progress. 



But with the range just measured off, great as it is, the limits 

 of the province of the van 't Hoff-Arrhenius theory are not 

 yet reached. The dissociation discovered by Arrhenius is 

 an electrolytic one. Accordingly, the immense number of 

 phenomena, in which the electrically charged ions participate, 

 belong likewise with those which here receive a new light. 

 The question as to the source and maintenance of the electrical 

 energy in the galvanic elements, as to the conduction of current 

 in electrolytes, as to the meaning of galvanic polarization, are 

 only single points in this field. Electro-chemistry in the widest 

 sense, and, indeed, as much so that part which is concerned 

 with essentially electrical questions as that which studies chemical 

 questions, has already received most valuable furtherance from 

 our theory, and has yet more in prospect. 



It is natural, as against this exposition, to propose the question 

 how the theory of van 't Hoff and Arrhenius has responded to 

 the requirements which have been made upon it in a so extra- 

 ordinarily wide-reaching and varied manner. Since I belong to 

 the few who make use of this aid in their investigations, I must 

 freely confess that my judgment in this matter may be looked 

 upon as subjective ; but since, on the other hand, I hold to both 

 theories unfortunately, not the position of a father, but only that 

 of an uncle of rather distant relationship, you may trust me that 

 at the time of first meeting them I was rather inclined to repel 

 than to greet them. I can then only personally declare that 

 no scientific idea produced in my time has assisted me in such 

 measure as has this one, and that I have further gained the im- 

 pression that the great scientific fields named have received 

 likewise unusual furtherance from this idea. In particular the 

 extraordinarily manifold and severe test which lies in the 

 numberless numerical consequences of the theory in all possible 

 fields, has yielded such a number of confirmations that the 

 relatively rare cases where the unprejudiced decision was 

 "insufficient" entirely vanish. Naturally must not be con- 

 sidered the judgment of those who, with insufficient qualifica- 

 tions, set themselves up as judges, who do not attempt to test 

 the theory, but only to refute it. The misunderstanding and 

 false conceptions from which such "refutations" proceeded 

 have been in fact of such kind that thereout no real progress, 

 which is the end of every scientific undertaking, has resulted. 



I hasten to close. The concise review of the working ground 

 of general chemistry, which I have just attempted to give, shows 

 to what great extent chemistry has made use of physical means 

 to solve her problems. It is, therefore, not especially necessary to 

 urge my chemical associates that they should follow up the study 

 of physics and acquire the necessary mathematical knowledge. 

 It is cared for at many Universities by the more far-seeing 

 teachers of chemistry, that this indispensable knowledge is 

 made as accessible as possible to our youths, and my personal 

 experience has shown me that such opportunities are gladly and 

 profitably used. 



But the reverse does not present so favourable an aspect. 

 The science of physics requires for its extension and develop- 

 ment exhaustive chemical knowledge in many directions. .A.11 



phenomena m which the special character of matter comes into 

 question require for their study an extended knowledge of just 

 this character, i.e. chemical knowledge. And I cannot avoid 

 complaining that in this direction too little is done. In the 

 more recent physical literature, I have met not seldom chemical 

 views, which were, in short, fearful, and which gave to the 

 mterpretation of the observed phenomena an entirely false 

 direction. The physicist is only loo inclined to consider 

 chemistry as an inlerior science, of which he knows a ^reat suffi- 

 ciency if, in the early part of his student life, he has once heard 

 its lectures. Nothing can be more wrong than such a view. By 

 reason of its richer and more special store of facts, chemistry 

 really remains behind physics in il^ development into a rational 

 science, and it will ever so remain, in the same way as physics 

 remains behind astronomy or mathematics. But directly for this 

 reason the beginning of the student years is the only time in 

 which to become acquainted with the varied details of chemical 

 phenomena, and to take up the enormous range of experienc 3 here 

 offered. For, according to experience, the physicist never learns 

 them later. The history of our science points out a number of 

 men, who, from chemists, have become physicists of high rank ; 

 I need name only Regnault, Faraday, Davy, Magnus, Hittorf. 

 But I cannot name a single man of science who, after having been 

 trained as a physicist, has made one purely chemical discovery 

 of importance, for it never occurs that a physicist later learns 

 chemistry. The great range of empirical experience can only 

 be incorporated into the memory at a time when the latter is 

 fresh, and it is usually already too late but a few semesters after 

 the student life has been begun. 



I can, therefore, not urge my physical colleagues enough : 



send your students at first for a few semesters into the chemical 



laboratory. We chemists must indeed do our part, in suitably 



I rearranging the laboratory instruction ; the practice in qualita- 



I tive analysis should, in particular, be greatly cut down, and in 



its place preparative work in its widest sense, together with the 



I typical forms of quantitative analysis, should be taken up. But 



since the same requirements are to be made upon the education 



of the future teacher of the natural sciences and mathematics in 



the Gymnasia and Reahchulen, it will not be difficult to soon 



find the methods best adapted for the chemical education of all 



non-chemists, without injuring the immediate purpose of the 



chemical laboratories — the training of chemical specialists. 



THE GENERAL CIRCULATION OF THE 

 A TMOSPHERE.^ 

 TF the question of the general circulation of the atmosphere 

 were referred to a meeting of educated people, one might 

 be sure that ninety out of a hundred who could give any answer 

 at all would explain it by the time-honoured equatorial and polar 

 current ; if anyone initiated in the subject sat near, one would 

 observe a pitying smile upon his lips, and, if asked for his 

 opinion, he would relegate that current, of sacred memory, to 

 the region of the fables, or at most only allow it to hold sway, 

 with certain limitations, in the tropical and sub-tropical zones, 

 the region of the trade -winds ; the temperate and cold zones 

 however would be reserved for the dominion of the variable 

 winds, and of newly arisen cyclones and anticyclones, of which 

 we cannot tell whence they come and whither they go, i.e. for 

 the origin and disappearance of which we cannot lay down any 

 laws. And if there were several of these initiated persons present, 

 a discussion would at once occur, from which no one could obtain 

 a clear idea, and which would leave everyone with the impression 

 that nothing certain was known about the subject. I suppose 

 that you have been present at such a discussion, and have appealed 

 to me to explain to you the present state of our knowledge of 

 this subject. 



I undertake this task the more willingly, since the question 

 of the general circulation of the atmosphere has but recently 

 entered upon a new stage, which marks a great step towards the 

 complete solution of the question, and becanse it is very desir- 

 able to obtain as wide a diffusion as possible for this theory 

 which corresponds to the present state of the science. 



In this question especially, as in many others, the history of 

 the development is exceedingly instructive, and of the greatest 

 value in aiding a comprehension of the subject. I propose, 

 therefore, that you should follow me through the different stages 



' Translation of a lecture delivered by Dr. J. M. Pemter before tfie Scientific 

 Club in Vienna. 



NO. 



73, VOL. 45j 



