Majf6, 1880] 



NATURE 



of chemistry, beginning the study of the carbon com- 

 pounds with the aid of this manual, to gain any but most 

 hazy ideas regarding the general scope of this branch of 

 the science. 



But notwithstanding such defects as those we have 

 mentioned there can be little doubt that M. Wurtz's 

 book is possessed of many admirable qualities. In place 

 of masses of unconnected facts he presents the student with 

 carefully-selected leading data ; he may, we think, strain 

 some of his favourite theories too much, yet he inculcates 

 the paramount necessity of theoretical explanations ; he 

 gives prominence to generalisations, such as equivalents, 

 combining weights, and laws of multiple proportions, 

 nomenclature and notation, bases, acids, and salts, (Sic. 

 &c., and these he develops historically with great clear- 

 ness and rare felicity of illustration ; and he gives just 

 sufficient detail concerning chemical manufactures as 

 suffices to render these intelligible to the ordinary student 

 of chemistry. 



The translation appears to be admirably executed. 

 The book is well printed, and the illustrations are distinct. 

 But why should one be led to believe that spirit-lamps 

 and charcoal-furnaces are still the ordinary appliances 

 for raising the temperature of substances in chemical 

 laboratories ? 



In reading the historical notes which are given con- 

 cerning most of the important compounds and generalisa- 

 tions of chemistry, one is ahiiost persuaded to believe 

 that, after all, '' chemistry' is a French science." 



M. M. P. M. 



OUR BOOK SHELF 



The Ceolos^ical Antiquity of Insects. Twelve Papers on 

 Fossil Entomology. By Herbert Goss, F.L.S. 8vo, 

 pp. 1-50. (London: John ^'an Voorst, 1880.) 



This bulky pamphlet must prove decidedly useful both to 

 geologists and entomologists. The subject of fossil ento- 

 mology has of late assumed gigantic proportions, and 

 -asserted an importance little dreamt of when pala:ontology 

 first substantiated its claims as the real guide to geologists 

 in determining the nature of many strata. Indeed, as is 

 truly stated by Mr. Goss, the wonder is that remains of any 

 animals so fragile as insects could have been preserved 

 sufficiently for scientific purposes ; yet we find contempo- 

 raneous with the remains of those marvellous Devonian 

 fishes those of the earliest types of insects, chiefly only 

 ■wings, it is true, but wings in such a complete state of 

 preservation that the intricacies of neuration can be 

 traced; and this neuration is in some cases so difficult to 

 homologise with that of existing forms that a separate, 

 supposed extinct order {Palaodiciyoptei-a) has been 

 formed fprobably unnecessarily) for the reception of these 

 remains. Mr. Goss has given detailed accounts (with 

 <:opious references) of almost every described species of 

 fossil insect from the older formations, and has contrived 

 to very lucidly place before his readers the sequence of 

 ■appearance of the now-existing orders according to the 

 testimony of the rocks. As we ascend in the geological 

 scale the indications become less complete, and only 

 genera, or eventually only families, are alluded to, but 

 always with the same copious references to authorities. 

 It could not be otherwise. As we ascend the materials 

 increase enormously, until at last, in the post-tertiary 

 system, we find ourselves in the presence of remains that 

 have been identified with species now living in the same 

 disU'ict ; and in somewhat less recent strata in North 



America the multitude of fossil remains of insects is 

 such as to place it out of the question that any detailed 

 account could be given of them. Not the least useful 

 feature in the work consists in the notes on the correla- 

 tion of special insect-forms with the most remarkable 

 animal and vegetable relics from the same formations. 



This pamphlet has no claims as embodying the re- 

 sults of original research ; it is a useful concentrated 

 compilation from the literature on the subject by one 

 who evidently has an intelligent knowledge of it both in 

 its geological and zoological aspects, and as such cannot 

 fail to be of service as a text-book, giving the student a 

 clear outline sketch, and the references where to seek 

 more detailed information. Such a w-ork [is often more 

 useful than original essays, which, from the magnitude of 

 the subject, can only be limited in their aim. The treat- 

 ment may be a little unequal, and we think it would be 

 possible to point out cases in which certain fossil-insects 

 have been referred to a wrong position ; but this is the 

 fault of the original describers. 



We are rather sorry to see that all notice of Amber- 

 Insects is intentionally omitted for the present, more 

 especially as, from the medium in which they are pre- 

 served, these are the most perfect of all fossil insect- 

 remains. They consist for the most part of well-marked 

 existing genera, but we think no one has yet dared to identify 

 any amber-insect with an existing species. In connection 

 with this subject one word of caution to palasontologists 

 with regard to many fossil insects. We find many insects 

 (excluding those in amber) referred to modern genera, 

 and even among those from ancient strata. This is a 

 convenience only; it indicates that certain fossils pre- 

 sent the general appearance of the existing genera to 

 which they are referred ; but in the majority of instances 

 it does not prove that they would be so refen-ed if the 

 remains were in the same condition as the recent materials. 

 In most cases we think it would be otherwise. 



The substance of this pamphlet originally appeared 

 as a series of introductory papers in vols. xv. and xvi. of 

 the Entomologists' Monthly JSIagasine, but the reprint 

 contains additional matter. 



LETTERS TO THE EDITOR 



[T/ie Editor does not hold himscll responsible for opinions expressed 

 by his cori-espondtnts. A^eithcr can he undertake to return, or 

 to correspond with the writers of, rejected viamiscripts. No 

 notice is taken of anonymous communications. 



[ The Editor urgently requests correspondents to keep their letters as 

 short as possible. The pressure on his spare is so great that it 

 is impossible othei-uiise to ensure the appearance even of com- 

 vutnications containing interesting and novel facts.'] 



The Opportunities of Science Masters at Schools 

 In consequence of my publisliing in your columns some facts 

 on visual and other memory, I have been favoured with letters 

 from many persons and from many countries ; few however have 

 been more acceptable than those from the masters and mistresses 

 of schools. Confining my remarks for the present to the masters 

 of the larger establishments, I may mention that the science 

 masters- of Cheltenham and of Winchester have promised 

 assistance, but I write especially to acknowledge the aid already 

 rendered to me by Mr. W. II. Poole, the science master of 

 Charterhouse, and to make some comments thereon, in order 

 to show how wide and yet how neglected a field for original 

 research lies open to every schoolmaster. Mr. Poole has sent 

 me returns from all the boys wlio attended his classes — 172 in 

 number. He selected certain of my questions concerning visual 

 and other memory, he explained them clearly to the boys and 

 interested them in the subject, and then he set them the questions 

 to ansuer in writing, just as he would have set questions in the 

 ordinary course of school-work. Lastly, he forwarded to me 

 the replies in separate bundles corresponding to the different 

 classes, and each paper was numbered, so that if I wanted to 

 learn more about any of them and sent him the numbers, he 



