July 9, 190H] 



NATURE 



2 [Q 



importance none of these appliances is illustrated in 

 the book. Quay cranes also, a most important class, 

 are not represented, though some of them are capable 

 of dealing with loads up to 150 tons. 



We think that in one or two cases the matter might 

 have been arranged to rather better advantage, but, 

 on the whole, we have no hesitation in saying that 

 the book is an excellent contribution to the literature 

 of the subject, and embodies the result of no little 

 personal investigation and research. It is specially a 

 student's book, and will appeal more particular!}' to 

 those who are already equipped with some funda- 

 mental knowledge of hydraulics. The bool'C is clearly 

 printed and well illustrated. 



THE DISCOVERY OF THE WEIGHT OF THE 



AIR. 

 Essais dc Jean Rev, 1630. Edition nouvelle avec com- 



mentaire par Maurice Petit. Pp. xxvii+iqi. 



fParis : A. Hermann, 1907.) Price 7 francs. 



SHORTLY after Lavoisier had presented an account 

 of his researches on calcination to the Academy 

 of Sciences, the French chemist Bayen discovered in 

 the Bibliotheque royale a small volume dated 1630, in 

 which the discoveries and views of Lavoisier were seen 

 to be anticipated by nearly a centurv and a half. This 

 volume was the " Essays de Jean Rev sur la Recerche 

 de la cause pour laquclle I'Estain et le Plomb 

 augmentent de poids quand on les calcine," of which 

 a translation in English was published some years 

 ago under the auspices of the Alembic Club (1895). 

 By a curious coincidence, the title of Lavoisier's 

 memoir, " Sur la calcination de I'etain dans les 

 vaisseaux fermes et sur la cause de 1 'augmentation de 

 poids qu'acquiert ce metal pendant cette operation," 

 was almost identical with that of Key's essays; an I 

 it is remarkable that the study of the behaviour of 

 the same metal, tin, when calcined, led both chemists 

 to arrive at a correct interpretation of the nature of 

 combustion. 



The salient characteristic of Rey's work is that he 

 concentrated his attention on the increase of weight 

 of metals during calcination, and was thus led to 

 recognise that the air has weight prior to the investi- 

 gations of Torricelli in 1643 and of Pascal in 1648. 

 The increase of weight was explained as follows : — 



" Ce surcroit de poids vicnt de I'air, qui dans le 

 vase ,a este espessi, appesanti et rendu aucunement 

 adhesif, par la v^hemente et longuement continuee 

 chaleur du fourneau ; lequel air se mesle avecques la 

 chaux (a ce aydant I'agitation frequente) et s'attache 

 h. ses plus menues parties." 



The object of the new edition of Rev's works 

 appears to be, not so much to direct attention to the 

 part played by Rey as chemist and precursor of 

 Lavoisier, but to put in a claim on his behalf as the 

 discoverer of the weight of the atmosphere and as 

 inspirer of the later work of Torricelli and Pascal. 

 When's Rey's "Essays" were printed in 1630 at 

 Bazas, in a form hardly likely to attain much pub- 

 licity, a copy came into the hands of a certain Frichet, 

 a lawyer of Bordeaux, who placed the results before a 

 circle of learned friends who assembled weekly in the 

 NO. 2019, VOL. 78] 



rooms of the Pere Mersenne at the mon.istery of Les 

 Minimes, in Paris. Pere Mersenne became the corre- 

 spondent of Jean Rey, and, it would appear, com- 

 municated the latter's investigations to Torricelli, 

 Galileo, Descartes, and Pascal, with whom he 

 was in constant correspondence. Thus Rey's book 

 " loin d'avoir iti un eclair de genie inconnu, ignore, 

 comme on I'a suppose jusqu'ici, devient le point de 

 depart de cette memorable campagne scientifiquc qui 

 se termina par les vic'.orieuscs experiences de Rouen 

 et du Puy-de-D6me." 



In support of these contentions a number of letters 

 of Jean Rey and of Pere Mersenne are published, and 

 the relationship of Mersenne with his great contem- 

 poraries traced in detail. Fremy long ago expressed 

 the conviction that the lack of appreciation of Rey's 

 work as compared with that of Torricelli and Pascal 

 was "one of the great injustices committed in the 

 historv of science." The editor of the new edition of 

 the " Essavs " aims at rectifying this injustice, so 

 that Jean Rev may take rank not merely as a chemist 

 and first discoverer of the part played bv air in com- 

 bustion, but as one of the founders of modern phvsics. 



W. A. D. 



OUR BOOK SHELF. 



Plant Anatoinv from the Standpoint of the Develop- 

 ment and Functions of the Tissues, and Handbook 

 of Micro-tcchnic. By Prof. \\". C. Stevens. Pp. 

 xii+349. (London: J. and .-\. Churchill, igoS.) 

 Price los. 6d. net. 

 .According to the axiom that the greater contains 

 the less, there is justification for the title of the book, 

 but so far as histology is distinguished from anatomy, 

 the contents pertain rather to the domain of histology. 

 This does not, however, correctly explain the nature 

 of the subject-matter, as the author has followed the 

 modern, and one has no hesitation in saying the best, 

 practice of uniting the study of form and function ; 

 in fact, each chapter is devoted to a separate physio- 

 logical problem. The arrangement is an excellent 

 one for an elementary book, but it must be added 

 that there is no attempt to rise beyond elementary 

 facts. The difficulties of the stelar theory are avoided 

 bv reverting to the older conception of protoderm, 

 procambium strands, and fundamental meristem. 

 " Bast fibres," as here explained, also show a return 

 to an older, though in this case less acceptable, de- 

 finition, and the nicer subtleties of distinction between 

 fibrous cells and wood fibres are omitted. The care- 

 ful and detailed descriptions of such processes as the 

 conduction of water and solutes through the stem will 

 be fully appreciated, but in places the author shows 

 but small regard for the intuitive perception of the 

 student (vide figs. 56, 87, and 92). The practical ex- 

 amples quoted at the end of the chapters are useful, 

 and the general presentation of the subject-matter is 

 marked bv clearness and coordination. 



Following on the course of anatomy is a handbook 

 of micro-technique. This science has been eagerly 

 absorbed by -American students sojourning in Europe, 

 with the result that their experience has spread like 

 leaven throughout the numerous colleges and univer- 

 sities in the L'nited States. The instructions here 

 conveved represent the most modern and approved 

 practice. In this country it is not the custom to push 

 students into complex fixing and staining methods 

 until they reach the advanced or research stage, so 

 that it appears inconsistent to devote a third part of 



