320 



NATURE 



[January 31, 1901 



from every point of view, a happy one. During his leave 

 of absence, Gerhardt came to Paris ; and again, it is 

 strange to us on the other side of the Channel, many of 

 whom are content with an occasional visit to the capital, 

 to see how absence from Paris is, to a Frenchman, ab- 

 sence from civilisation. " La vie du province" — there is 

 no expression which so fitly renders the ^«?««" of banish- 

 ment from " ce cher Paris." But to live at Paris was not 

 necessarily to find an official position ; and, after many 

 disappointed hopes, Gerhardt finally accepted two chairs 

 at Strassburg ! " Le cumul," as pluralism is termed, has 

 attractions, it appears, to those to whom it is offered. 



Gerhardt was not long at Strassburg, however, before 

 he succumbed to an attack of peritonitis ; and, after a 

 i&'fi days' illness, during which he regretted nothing more 

 than the cessation of work, he passed away. 



Gerhardt shared with other reformers absolute belief in 

 his own theories, and want of patience with conservatives 

 who would not be convinced. Patience and a more 

 gracious manner would have not only given him a hap- 

 pier and more prosperous career, but would also have 

 accelerated the acceptance of his doctrines. Still, it is 

 difficult for us to judge. Suffice it to say that the 

 formulae which we still use are, for the most part, Ger- 

 hardt's. While Gerhardt referred the formula; of com- 

 pounds to the volume occupied by the molecular weight 

 in grams contained in 22*4 litres of the gas, Laurent ex- 

 tended the same numerical conception to the " formul;e " 

 of elements ; while Gerhardt wrote HgO for the formula 

 of water, but O for that of oxygen, Laurent introduced 

 Avogadro's and Ampere's view that the molecular 

 formula of oxygen should be O2. They united their 

 forces in advocating the adoption of "types," such as 

 that of H2, HgO, and NH3 ; and Williamson supple- 

 mented their ideas by the addition of " double types " — 

 substances derived, for example, from two molecules of 

 water by replacement of an atom of hydrogen in each. 

 Later, as every one knows, this conception developed 

 into structural formulcC. But the idea of a homologous 

 series, too, was first introduced by Gerhardt ; and it 

 has proved one of the most fertile in the whole domain 

 of organic chemistry. 



We have witnessed as great, if not a greater change in 

 chemical theory during recent years. Fortunately, it has 

 not aroused the same passion, although it has been reso- 

 lutely opposed by a conservative faction. At the meeting 

 of the French Association at Havre, the writer remembers 

 well a discussion of which the central point was whether 

 the formula of barium sulphate should be written 

 BaO.SOj or BaS04. Is it possible that, twenty years 

 hence, v/e shall still find a remnant for whom the ionic 

 theory has no value ? W. R. 



MONISM FOR THE MULTITUDE. 

 The Riddle of the Universe at the Close of the Nineteenth 

 Century. By Ernst Haeckel, Ph.D., M.D., LL.D., 

 Sc.D., and Professor at the University of Jena. 

 Translated by Joseph McCabe. Issued by the 

 Rationalist Press Association, Ltd. Pp. xvi + 398. 

 (London : Watts and Co., 1900.) 



THERE is a twofold pathos in this book, for with it 

 the author — whom to know is to love — draws, he 

 says, "a line under his life-work," and with it he once 

 NO. 163 1, VOL. 63] 



more illustrates the sad fact that a great investigator 

 may not be convincing as a philosopher. The book 

 begins with a reproach that philosophy is ignorant and 

 that science lacks consistency, and we end it with a sigh 

 for the same reasons. As a few readers may remember, 

 Haeckel projected, almost a generation ago, the scheme 

 of a " System of Monistic Philosophy" ; but the shadow 

 of age has fallen upon him while his early ambition was 

 still not within sight of being realised. Therefore he has 

 given us in this, " which has something of the character 

 of a sketch-book," only a hint of what might have been. 

 For the non-fulfilment of his dream of youth, the order 

 of things is more responsible than the author, for there 

 are few who have worked harder and, at the same time, 

 more brilliantly for their day and generation. 



But although Haeckel speaks of the volume as a sort 

 of sketch-book, this is not meant to suggest that its 

 conclusions are mere obiter dicta. On the contrary, as 

 he tells us, he has been meditating for fully half a century 

 on the problems of evolution, and now, in his sixty-sixth 

 year, he gives us " the ripe fruit of his tree of knowledge." 

 If this is not an altogether happy metaphor, it may 

 serve to remind the unsympathetic that we have here, 

 at least, the sincere voice of " a child of the nineteenth 

 century," who is conscious of no dogmatism, though the 

 suggestion of it seems painfully frequent, who blinks no 

 facts so far as he is aware, who is impelled by no motive 

 but a love of truth. 



" My ' Monistic Philosophy ' is sincere from beginning 

 to end — it is the complete expression of the conviction 

 that has come to me, after many years of ardent research 

 into Nature and unceasing reflection, as to the true basis 

 of its phenomena." 



Impulsive the author certainly is, as he has always 

 been — impulsive, for instance, to champion Darwinism 

 in the early days of its unpopularity, and impulsive in 

 his confidence in genealogical trees which many a Jack 

 has hewn at while the giant climbed — but ignorant no 

 one will venture to call the zoologist who has laid so 

 many solid blocks in the scientific edifice, and to whom 

 the Royal Society has lately awarded its Darwin medal. 

 There is, perhaps, no important idea in this volume, ad- 

 mirably translated by Mr. Joseph McCabe, which is not 

 to be found in that wonderful work of 1866, the " Generelle 

 Morphologie " ; but the ideas are now illumined with a 

 wealth and confidence of illustration which only a big 

 personal share in the scientific progress of the last forty 

 years could give. 



The book, as we have said, begins with a reproach. 

 Scientific workers " do not see the wood for the trees " ; 

 the metaphysicians " trouble not about the individual 

 trees, and are satisfied with the mere picture of the 

 wood" ; betwixt the two is the multitude, still oppressed 

 by " the riddle of the painful earth." But this incoherence, 

 this ignorance, this oppression result from that blind- 

 ness to the open secret of unity which is the lasting 

 defect of Western thought. There is but one fact, and, 

 as a writer in the Monist recently remarked, it is an 

 evidence of human frailty that the word ever got a plural ; 

 there is but one science, the science of the order of 

 nature ; there is but one comprehensive riddle, the 

 problem of substance ; and there is but one hopeful 

 attempt at Solution, namely, of course, scientific monism. 



