NA rURE 



[December 31, iqo8 



Parry's book. Incidentally the question of what is 

 brandy is elucidated by what is stated respecting the 

 nature of artificial cog^nac oil, which, however, strictly 

 speaking, is not an essential oil. There is, as the 

 .luthor says, an almost unlimited field of research in 

 the synthetic production of perfumes. The field is still 

 practically unfilled, and ,i rich harvest awaits the 

 successful cultivator. 



It is, however, a moot point whether any individual 

 synthetic perfume is the equal, from the perfumer's 

 point of view, of the corresponding natural perfume. 

 Some of these synthetic perfumes in the pure or con- 

 centrated state in no wise resemble the natural variety; 

 in fact, in this state they are .•ilniost repellent, and it 

 is only when judiciously blended .ind diluted lh;il their 

 fragrance becomes pleasurable. 



The fragrance of a natural perfume is in all prob- 

 ability not wholly due to a single substance or a single 

 stimulus. .Some one substance m.iy hr ilurr in rela- 

 tively large proportion, but associated with it .ire other 

 odoriferous substances, some of them, possibly, in 

 minute .amounts only, bul .all of them contributing 

 to an olfactory .sensation which gives pleasure. .\ 

 p< rfume, in fact, is like a piece of music. There may 

 be in the piece a dominant musical idea, but the 

 pleasure it creates is largely dependent upon its 

 association with tone-sensations which are not neces- 

 sarily structural parts of the dominant idea. 

 ■Synthetic perfumes, therefore, can only successfully 

 replace natural perfumes when the greatest care and 

 judgment are exercised in blending. This kind of 

 blending rises to the level of a fine art. To be suc- 

 ■cessful in its e.xercise the olfactory sense of the blender 

 requires a training hardly less rigorous than that 

 required by the auditory sense of the musici.an. 



This work, with all its limitations, is still the most 

 complete treatise on the subject in our langu.age, and 

 as such is indispensable to the pharmacist, the per- 

 fumer, as well as to the analytical chemist who may 

 be concerned with the examin.-iiion of a class of sub- 

 stances of varying char.-Klrr .ind peculi.irlv liable to 

 sophistication. 



-1 MO.XOGRAPJI OX THE FROG. 

 Ihr Frosch. Moiio^^rnphivii cvihciDiischcr Ticre. 



Band i. By Dr. F. Ih nipelm.inn. Pp. vi+201. 



(Leipzig: W. Klinkhardt, u,o8.) Price 4.80 marks. 

 ^T^HIS monograph, the editor informs us, has arisen 

 -*• in connection with elementary biological teach- 

 ing at Leipzig, and is intended to describe not onlv 

 the habits, structure, and development of " the physi- 

 ologist's domestic animal," but to form ;in introduction 

 t<i physiology, psychology, the mechanics of develop- 

 ment, classification, and distribution. It is in respect 

 of its scope that this addition to the \ast literature on 

 the frog differs from its predecessors. .Vt the same 

 time it is written for beginners, and must be judged 

 from its value as an introductory handbook to practical 

 dissection and experiment 



We may say at once that takeji as a whole it is a 

 well-written and successful attempt to compress all 

 that is important and well established concerning the 

 NO. 2044, ■^'OL. 79] 



frog into 200 pages. But that is far more than an ele. 

 mentary student can assimilate, and between what h.' 

 is first to notice and what he will onlv notice aftii 

 the primary difficulties are overcome there is no means 

 of distinguishing. 



We regret that no mention is made of Marshall ^ 

 famous book, and also that figures taken from hi-, 

 works are borrowed merely from reproductions of them 

 by other authors. This neglect of Marshall is, how- 

 ever, no isolated case of the omission of some of tin- 

 most important English works on the frog, both 

 educational and other. There is surely no more im- 

 portant work on the distribution and systematic aspect 

 of .\m|)hibia than Boulenger's " Tailless Batra- 

 chiiuis," nor is there a more readable account of the 

 various .aspects of this very animal than that bv 

 Holmes, published some two years ago. Lister's 

 classical researches on the pigmented cells .are nowhere 

 referred to, whilst a sm;dl .-md .ilniost unknown com 

 pilatiun by .St. John .Miv.irt mure than thirl\ \e;ir>. 

 old is quoted. 



The first section, that on anatomy, is based on 

 Gaupp's well-known edition of Helper's work. His 

 tology begins on p. b, and the student is plunged into 

 a study of the structure of the integument before the 

 terms " cell," " transverse section," ;nid " gland "are 

 made clear. The apparently inevit;d;le and complicated 

 nomenclature reaches its maximum in connection with 

 the brain, where no fewer than four sets of terms are 

 used for each region. The difficult and complicated 

 question of how the heart distributes arterial and 

 venous blood requires a fuller sketch of the heart itsell 

 than is given on p. 54; whilst the equally difficult 

 problems of development, e.g. of what are meant 

 b,' " pronephros " and " mesonephros," are scarcely 

 .alluded to. The writer does not seem to appreciate the 

 difficulties of beginners in reg.ard to these unfamiliar 

 conceptions. 



The second section —physiology — is nuah better 

 done, and the gener.al features of metabolism are 

 clearly explained. Then follow sections on heat-pro- 

 duction, colour-change, movements, and the elementary 

 physiology of muscle and nerve, le.-iding up to a dis- 

 cussion of psychology and the development of con- 

 sciousness. Some account is given of the experimental 

 side of development, in which, however, we miss any 

 reference to Assheton's work on the growth of different 

 regions; in f.ict, the phenomenon of growth does not 

 appear to be treated anywhere in the book. The re- 

 ferences to sex-determination (p|). 1(12-4) in our present 

 ignorance are inconclusive, and might well have been 

 omitted. 



Lastly, we come to " Biologie " (it is difficult to see 

 why this, the most interesting part of a treatise, is 

 .always put at the end by German writers) and classifi- 

 cation. Here we must agree to differ from the author. 

 The common brown grass frog has always been Kaiici 

 tcmporaria to us, but to find it described as Kaua mitta 

 laurcnli is indeed a shock. There is really no good 

 ground for this change. The tendency needlessly to 

 upset well-established n.imes is a most regrettable 

 feature of systematists ; but to introduce confusion 

 without any right, explanation or apology into a book 



