6o2 



NA TURE 



[April 28, 1892 



therefore no free affinities " ? This example shows that 

 the paragraph quoted above from p. 76 is much too 

 dogmatic. 



I do most strongly object to such a statement as that 

 on p. 69, where, speaking of carbon monoxide, it is 

 said : — 



"The molecule of this compound is represented by the 

 formula 



*z:ci!o. 



Here the asterisks are intended to show that two affini- 

 ties are unsaturated ; this is proved by the fact that the 

 compound unites with two atoms of chlorine, forming 

 phosgene gas, 



CK 



>C=0." 



qv 



What is proved by the fact of combination with 

 chlorine ? No one can attach any clear meaning to the 

 statement " two affinities are unsaturated." The only 

 practical meaning these words have is, " The molecule 

 CO can unite with two other atoms of certain kinds " ; 

 that is to say, the sentence quoted, when put into the 

 speech of the plain man, asserts that the fact that CO 

 does unite with 2CI proves that CO can unite with 2CI. 



The later paragraphs, treating of the physical properties 

 of bodies and the connexions between these and the con- 

 stitutions of the same bodies, seem to me to be both very 

 well done and very disappointing. They are well done 

 because an earnest attempt is made to put the matter 

 clearly, but they are disappointing because it is quite im- 

 possible to grapple with these very difficult matters in the 

 space which is given to them in this book. I do not think 

 that anyone will succeed in getting a grasp of Raoult's law 

 from the pages which are grouped around paragraph 133. 

 The application of Raoult's law to determine molecular 

 weights, given on p. 137, is based on the constant -62°, 

 which has been shown by van 't Hoff and others to be 

 erroneous. 



But it is much easier to find fault than to compose such 

 a book as this. A careful perusal of the work leaves the 

 impression on my mind that, as a synopsis and suggestive 

 remembrancer to the student who knows general chemistry 

 well, this book will prove useful, but that it is too con- 

 densed and too slight to be of much service to him who is 

 beginning the study of general chemistry. Most of the 

 subjects dealt with cannot be made clear except by going 

 into details, and illustrating them with considerable profu- 

 sion. When one attempts to deal with these matters in 

 a broad and general way, and at the same time to devote 

 only a few pages to each section, one is almost obliged 

 either to make statements so generalized that they are of 

 very little use to the earnest student, or only to touch the 

 fringe of each part of the subject. Chemistry is an abstract 

 science to a much less degree than physics ; hence such 

 short statements as those which sum up and include in 

 themselves whole provinces of physical knowledge cannot 

 yet be made in chemistry. Where the " Outlines of Theo- 

 retical Chemistry " fails for the most part it fails because 

 no book could succeed ; it fails because it attempts to do 

 that which cannot, at present, be done. 



M. M. Pattison Muir. 

 NO. 1 1 74, VOL. 45] 



THE TRAVELS OF A PAINTER OF FLOWERS. 



Recollections of a Happy Life, being the Autobiography 

 of Marianne North. Edited by her sister, Mrs. John 

 Addington Symonds. In Two Volumes. (London r 

 Macmillan and Co., 1892.) 



MOST of the readers of Nature will know without 

 telling that Marianne North was a world-wide 

 traveller, that she travelled in pursuit of nature, that she 

 was an accomplished and faithful painter of plant and 

 animal life, and that the results of a life's labour were 

 presented by her to the nation, and now cover the walls 

 of a building in Kew Gardens, erected at her expense 

 Most persons, too, who knewj her personally — and her 

 acquaintances and friends are as numerous as her travels 

 were wide — will be glad to know something more of her 

 history, and especially something more of her travels, of 

 her impressions of peoples, of places, and, above all, her 

 impressions of the plant and animal life of the many 

 countries she visited and to which she gave her life. All 

 who had the pleasure of knowing her personally will 

 remember her stately presence, her kind face, her charm- 

 ing manner, and her entertaining conversational powers 

 — now relating the difficulties and delights of her expe- 

 riences in foreign lands, now her appreciation of home 

 comforts and genial society. She wrote as she talked, 

 and she was a fertile letter-writer ; and she has written 

 her book in the same style. 



In early life Miss North made various journeys in 

 Europe, and also went up the Nile and visited Syria, and 

 painted many flowers ; but with the exception of the Sici- 

 lian /'a//r«/j', and perhaps two or three other little pieces, 

 none of this early work is in the gallery at Kew. Only 38 

 pages of her book are devoted to her early life, and it prac- 

 tically begins with her more distant travels ; the first long 

 trip being to Canada and the United States, and extended 

 to Jamaica, whence she returned to England. Two months 

 later she started for Brazil, where she made a long stay, 

 and then returned direct to England. The next journey 

 included Teneriffe, California, Japan, Singapore, Borneo, 

 and Java, and then home again. Her paintings attracted 

 [ attention, and she complied with a request to exhibit 

 j some 500 of them at Kensington. This matter being 

 ! arranged, she proceeded to India, landing on the way at 

 j Lisbon, Gibraltar, Malta, and Galle ; and India was 

 \ traversed almost from east to west and north to south. 

 The narrative of this journey is perhaps the most in- 

 teresting part of the whole work. On her return home 

 there was an exhibition of the accumulated paintings in 

 Conduit Street ; and a visit to Mr. Darwin, which ended 

 in a determination to go to Australia and paint the 

 flowers of the fifth quarter of the globe. It should be 

 mentioned that in the meantime Miss North had adopted 

 a suggestion of the Pall Mall Gazette that her paintings 

 should find their home at Kew, and her generous offer 

 was accepted. So it was, that when Darwin told her 

 that her collection of paintings would be an imperfect 

 representation of the vegetation of the world without the 

 Australian element, she took it as a '' royal command," 

 and prepared to go forthwith. This journey some of the 

 old scenes were revisited, brief halts being made at Galle 

 and Singapore, a longer stay with the Rajah and Rani 



