December 8, 1910] 



NATURE 



165 



volumes, the available space of which has been still 

 further reduced by the numerous good illustrations 

 the editor gives us. There are, however, cases where 

 the really important information is not given. Take, 

 for instance, the note on Molinia coerulea. We are 

 told that it has the power of absorbing considerable 

 quantities of the salts of heavy metals, and a case is 

 quoted where the ash contained 2041 per cent, of lead 

 oxide, 0266 per cent, of copper oxide, and 0*265 per 

 cent, of zinc oxide ; further, we are told that it is 

 regarded as a bad pasture grass. Now molinia is a 

 weed and not a cultivated crop, and the things the 

 chemist wants to know about it are these : What soil 

 conditions does the presence of molinia indicate? and 

 has molinia ever been observed to produce any ill- 

 effect on animals? if so, what is the harmful con- 

 stituent? Information could have been given on the 

 first point that would have been valuable, for molinia 

 is a useful " indicator " plant. Again, we are given 

 analyses of animal excreta, but no mention is made of 

 the fact that the composition is very variable, nor are 

 we told whether the figures represent means of manj* 

 analyses or only one or two determinations. 



A more serious defect, however, is the omission of 

 references. The student is rarely told where to go for 

 fuller information, and it is practically impossible for 

 him to check the data given in the article unless he 

 knows his way about the literature of the subject. 

 It is inevitable that dictionary notes should be short 

 and should omit much ; their great value ought to be 

 the guidance they afford to the man who wants to 

 learn more. But even with this defect the volumes 

 are very useful, and will prove a distinct acquisition 

 to the agricultural chemist. E. J. Russell. 



RADIO-CHEMISTRY. 

 Radio chemistry. By A. T. Cameron. Pp. viii + 

 174. (London : J. M. Dent and Sons, Ltd., 1910.) 

 Price 25, 6d. net. 



THIS book purports to be an "exact account of 

 our present knowledge of the chemical properties 

 of the radioactive substances and their chemical 

 effects," and in the preface much stress is laid on the 

 "accuracy" of the facts and theories here presented. 

 It is further stated that the subject is " treated from 

 a chemical standpoint," while "the physical side is 

 introduced only so far as is necessary to explain the 

 special experimental methods." As to how well the 

 author has attained the latter object can be best judged 

 from two examples, one a description (quite in- 

 correctly asserted to be "that in Rutherford's ' Radio- 

 activity,' p. 86") of a Wilson type of electroscope 

 (p. 10), where, in addition to a very extraordinary 

 earth connection, the movement of the aluminium leaf 

 is observed by a "telescope" which "carries a scale," 

 a distinctly inconvenient and unusual arrangement ; 

 and the other a description of a Dolszalek electrometer 

 (p. 13) having "one pair of quadrants connected to 

 earth, the other to an insulated metallic plate facing 

 a second which carries the radioactive matter to be 

 tested." "Through action similar to that in the case 

 of an electroscope an electric stress is set up between 

 the two pairs," and "the needle, previously charged 

 NO. 2145, VOL. 85] 



to a very high potential, is repelled from one pair of 

 electrodes towards the other " ! 



The chapter on the "Classification of the Radio- 

 active Elements — their Physical and Chemical Pro- 

 perties " might be expected to justify the title chosen 

 for the book, but it is disappointing to an extreme 

 extent; the chemical properties of uranium, for ex- 

 ample, being, dismissed with the bare statement that 

 "it belongs to the iron group of elements and is 

 precipitated by ammonium carbonate." The discussion 

 of the identification of ionium is quite misleading, 

 and the account of the chemical properties of the 

 other radio-elements of a very superficial character. 

 The statement that thorium " occurs chiefly in Ceylon " 

 is certainly surprising. It is doubtful whether anyone 

 not already somewhat familiar with the subject could 

 separate or identify a single radio-element from the 

 directions which are given. 



Errors and misleading statements are not un- 

 common. Thus (p. 17) the simple exponential equa- 

 tion I,= Io^~^' is given in an inverted and incorrect 

 form, which again appears later (p. 90). Further 

 examples are the statements (pp. 56, 141) that radio- 

 thorium "is precipitated with barium," "resembles 

 radium in every respect," and has an activity "several 

 hundred thousand times that of radium " ; that in the 

 separation of uranium X by treatment with a mixture 

 of ether and water (p. 39) " the ether layer contains 

 most of the photographic or i3-ray activity " ; that the 

 active deposit from the radium emanation (p. 51) 

 "decays to half value in twenty-eight minutes, but 

 the decay curve is very irregular"; and that "the 

 actinium products have all extremely short lives so 

 that the maximum activity is quickly reached (p. 56). 

 The mention of the "decay curve of a radioactive 

 child " (p. 17) certainly suggests the most gruesome 

 possibilities ! 



B. B. Bolt WOOD. 



EGYPTOLOGICAL RESEARCHES. 

 Egyptological Researches. By W. Max Miiller. 

 Vol. ii.. Results of a Journey in 1909. Pp. v-f 188+ 

 47 plates. (Washington : Carnegie Institution, 

 1910.) 



FOUR years ago Herr W. M. Miiller, now of Phila- 

 delphia, published a first volume of " Egypto- 

 logical Researches," brought out at the expense of 

 the Carnegie Institution of Washington, which had 

 borne the expense of the journey to Egypt in 1904 

 the results of which were thus published by Herr 

 Miiller. In 1906 Herr Miiller undertook a second 

 journey to Egypt, and now publishes a second volume 

 of these "Researches." 



Herr Miiller 's chief aim on both journeys was to 

 pick up as much as possible of the hitherto unedited 

 and badly edited historical material which still is to 

 be found in the inscriptions of Thebes, notwithstanding 

 the labours of many Egyptologists. In his first 

 volume he published in colour the extant remains of 

 the famous pictures of Minoan Cretan ambassadors 

 in the tomb of Senmut, the prime minister of Queen 

 Hatshepsut, which are so important to the Greek 

 archaeologists. These pictures had already been pub- 



