540 



NATURE 



[October 8, 1891 



well-selected points of view, and admirably reproduced as 

 small quarto plates. These plates are striking illustrations 

 of what can be accomplished by instantaneous photo- 

 graphy as an aid to vulcanological study. Among them 

 are very instructive views of explosive outbursts from the 

 craters of Stromboli and Vulcano. In the case of the 

 small explosions from the first-mentioned volcano, the 

 ejected fragments are seen in the midst of the steam- 

 clouds ; and in the case of the more violent eruptions from 

 Vulcano several phases in the same outburst have been 

 caught at intervals of a few seconds. Those who already 

 know this very interesting district will be glad to have 

 their recollections revived by these admirable plates ; 

 and those who have never had the pleasure of visiting the 

 South Italian volcanoes may obtain from these remarkable 

 photographs a much better idea of the localities than any 

 descriptions or drawings can possibly give. 



Buried Cities and Bible Countries. By George St. Ciair, 

 F.G.S. (London : Kegan Paul, Trench, Triibner, and 

 Co., 1891.) 



Everyone knows that recent archaeological research 

 has brought to light a vast number of facts which are 

 directly or indirectly connected with ancient Hebrew 

 history. The object of the author of the present work is 

 to set forth the more important of these facts, and to 

 explain their significance. He deals with the results of 

 exploration in Egypt, Palestine, and Mesopotamia ; and 

 he has a chapter on Jerusalem, with regard to the topo- 

 graphy of which he has been led to conclusions different 

 from those of other writers. The book has been 

 prepared for the benefit of persons " who have no 

 time to follow the course of exploration, and no taste for 

 technical details " ; and readers of this class will find in 

 it much that will be to them both new and interesting. 

 The value of the text is increased by good maps, plans, 

 and other illustrations. 



Food, Physiology, &^c. By William Durham, F.R.S.E. 



(London and Edinburgh: A. and C. Black, 1891.) 

 This is the third volume of a series by Mr. Durham, 

 entitled " Science in Plain Language." The author does 

 not pretend to say anything new, but he has brought 

 together, and arranged clearly, a mass of facts which 

 will no doubt be of interest, and may be of practical 

 service, to many readers who have neither time nor 

 inclination for the study of more elaborate treatises. He 

 begins with the consideration of solid and liquid foods, 

 then gives some account of the constituents of food, and 

 finally sketches the structure and functions of the bodily 

 organs. 



Blackie's Science Readers. (London : Blackie and Son, 

 .1891.) 



The aim of this series is to arouse the interest of children 

 in the common objects of the natural world, and to give 

 them some insight into the processes by which articles of 

 ordinary use are produced. The idea is excellent, and has 

 been very successfully worked out. The series consists 

 of five little volumes, the first two of which present some 

 " lessons on common objects." From the third volume 

 the reader will learn something about the simple principles 

 of classification ; about substances used in arts and manu- 

 factures ; about phenomena of earth and atmosphere ; 

 and about matter in three states— solids, liquids, and 

 gases. The fourth and fifth volumes— by the Rev. 

 Theodore Wood— deal with animal and plant life. The 

 facts set forth have been carefully selected, and they are 

 presented in a bright, easy, natural style which cannot 

 fail to make them at once intelligible and attractive. 

 Good teachers will find the series of real service in 

 helping them to foster in the minds of their pupils a love 

 of accurate observation and independent reasoning. 

 NO. I 145, VOL. 44] 



LETTERS TO THE EDITOR. 

 [The Editor does not hold himself responsible for opinions ex- 

 pressed by his correspondents. Neither can he undertake 

 to return, or to correspond with the writers of, rejected 

 manuscripts intended for this or any other part of Yi kivr.%. 

 No notice is taken of anonymous communications. ^ 



Comparative Palatability, 



With the view of supplementing the experiments carried out 

 last year by Mr. F. Finn and myself (Nature, vol. xlii. pp. 

 571, 572), I have been feeding, during August and September, 

 specimens of the common frog and toad. 



Among Hymenoptera, Boiiibi are readily taken by frogs. I 

 have records of B. lapidarius (drones and workers), terrestris 

 (queens and workers), and muscorum (drones and workers). 

 On one occasion only a freely-feeding frog refused to attack for 

 the second time a large queen of terrestris, which had stung its 

 mouth. Manyof the insects were,however, thus taken at the second 

 attempt. The common wasp was eaten eagerly by frogs and 

 toads. I was again unfortunate in not taking any Chrysidida. 

 Sirex gigas was attacked both by a frog, for which it seemed too 

 large, and by a toad, under whose lip it appeared to insert its 

 ovipositor. Neither animal ventured to seize it again — certainly 

 for an hour or so. I was then obliged to abandon the observa- 

 tion. I could get no large ichneumon?. 



Of Lepidoptera, Vanessa urticce was taken by frogs and toads, 

 and V. io by a frog. Three or four specimens of Pieris rapce 

 and napi would be taken in succession by a frog, which also ate 

 P. brassiccE. The insects' flutterings did not seem to matter : 

 more than once they were taken on the wing. A toad once took 

 /-". rapcB. I was surprised to see a frog seize a dead specimen of 

 this butterfly, which had been lying for several hours in the in- 

 closure. It was partially swallowed, but rejected after some 

 seconds — having unfortunately been taken together with some 

 cedar needles. Plusia gamma was eaten eagerly by both frogs 

 and toads. Hairy caterpillars {e.g. of Orgyia antiqua and 

 Spilosoma sp.) were taken by a frog. Smooth green larvae were 

 eaten greedily. 



Of Diptera, Erisialis tenax was eagerly seized by frogs and 

 toads. A red-tailed, long-winged fly was eaten by a frog. 



Blatta orientalis was taken without hesitation ; as were, of 

 course, earthworms. 



Of three frogs under observation, only one was of much work- 

 ing value. This specimen (a male) became in a fortnight so 

 tame as to attempt to taka the handle of the butterfly-net with 

 which I placed the insects, &c., in the inclosure. This fact re- 

 calls Mr. E. B. Poulton's observation, that his tree-frogs seized 

 the end of the forceps with which food was given them. 



It is, perhaps, worthy of notice that the larvae of the blow-fly, 

 though eaten eagerly by toads, are frequently passed whole from 

 the body ; and would, therefore, seem to be with difficulty 

 digested. 



Want of time has prevented my experimenting, as I had 

 wished to do, with Salamandra maculosa. Mr. F. Finn offered 

 a specimen to ducks, which will eat the small newt, and found 

 that though more than one bird observed it, and one even ran 

 towards it, it was not touched. The observation extended over 

 more than an hour. E. B. Titchener. 



Mote House, Mote Road, Maidstone, September 25. 



Alum Solution. 



Dans le no. I141 de votre excellente Revue, M. Napier 

 Draper demande pour quelle raison la solution d'alun a ete uni- 

 versellement adoptee pour I'absorption des radiations de grande 

 longueur d'onde. Ce n'est point pour repondre a cette question 

 que je vous ecris, car, pas plus que votre correspondant, je ne 

 connais d'experiences directes suffisamment exactes desquelles il 

 resulterait que la solution d'alun absorbe plus que I'eau pure. 

 Je hasarderai, cependant, une explication : I'eau est un des 

 liquides transparents les plus absorbants ; I'alun occupe un rang 

 analogue parmi les solides ; en dehors de toute verification, si 

 I'absorption selective de chacun de ces corps s'exerce sur une 

 partie differente du spectre, on pent supposer que leur melange 

 exerce une absorption plus complete que chacun des corps pris 

 isolement. 



A cette occasion, je prendrai la liberte de relever une erreur 

 que Ton a frequemment commise dans ces derniers temps au 

 sujel de I'absorption des radiations infra-rouges par I'eau. On a 



