NATURE 



3*3 



THURSDAY, FEBRUARY 4, il 



CARPENTER BY DALLINGER. 

 The Mt, roscope and its Revelations. By the late William 

 B. Carpenter, C.B. M.D., F.R.S. Seventh Edition, by 

 the Rev. W. H. Dallinger, LL.D., F.R.S. (London : 

 J. and A. Churchill, 1891.) 



THE earlier editions of Dr. Carpenter's " Microscope" 

 had a satisfactory basis. They formed an excellent 

 guide to the use of the instrument, in days when micro- 

 scopic technique was far less elaborated than it is now, 

 written by an enthusiastic and experienced worker. Dr. 

 Carpenter told us about the theory of the microscopeandthe 

 different kinds of stages, rack- works, and objectives which 

 he himself had seen and tried ; and then gave a somewhat 

 casual and purely personal account of different animal, 

 vegetable, and mineral structures which had been investi- 

 gated with the microscope, and had especially excited his 

 interest and attention. The book was valuable because 

 it contained the advice and judgment of a great authority, 

 and original observations upon a heterogeneous assem- 

 blage of objects by a highly competent naturalist. The 

 later editions of the book, even in Dr. Carpenter's 

 hands, lost a good deal of the original character of the 

 work. New matter of all kinds was fitted in, until the 

 volume became very bulky. Still, the selection of 

 material was made by one man, and the work might be 

 regarded as his note-book, his conception of what was 

 most interesting and instructive in the wide field of 

 microscopic research. An edition of such a book by 

 other hands after the death of the original author is 

 not likely to be a real success, though it may justify a 

 publishers commercial foresight. Dr. Carpenter's name 

 is a good one to trade with ; but as a matter of fact there 

 is not much of Dr. Carpenter in the present work, and 

 what there is has only impeded the naturalists who have 

 assisted Dr. Dallinger in elaborating its contents. The 

 result is very confusing : the reader often is at a loss to 

 know whether a statement is one surviving from Dr. 

 Carpenter himself or is introduced by the new editor. 



The book really consists of five treatises compressed into 

 a single volume, no one of which excepting the first is 

 by any means complete. These treatises are : (1) on the 

 theory of microscopical optics, and the history and pre- 

 sent development of the compound microscope and 

 accessory instruments ; (2) on microscopic technique ; 



(3) on the vegetable kingdom and vegetable histology ; 



(4) on the animal kingdom and animal histology ; (5) 

 on the microscopic structure of minerals and rocks. 



The first of these treatises is a new and original work by 

 Dr. Dallinger, and occupies five chapters. It contains a 

 valuable exposition of the theory of modern objectives, 

 and some interesting records of ancient microscopes. 

 The statements on p. 209, as to the introduction of the 

 Hartnack model and objectives into this country, and the 

 motives which led to it, are entirely erroneous. I had a 

 large share in that innovation ; and i have no hesitation 

 in stating that what led to the importation of German 

 and French microscopes direct from their makers was the 

 simple fact that one obtained an efficient instrument for 

 about one-fourth of the price exacted at that time by 

 NO. 1 162, VOL. 45] 



English makers for an instrument of no greater practical 

 value ; whilst it was also the fact that English dealers 

 (not the great makers) were in the habit of selling inferior 

 Continental objectives (rejected by their makers) as their 

 own "make," at higher prices than would suffice to pur- 

 chase first-rate glasses from the Continental firms. The 

 result of the diversion of English purchasers to Con- 

 tinental stands and objectives was the simplification of 

 English models, and an enormous reduction in the price 

 of English-made objectives. 



The treatise on section-cutting, mounting, use of re- 

 agents, &c., is necessarily short, and lacks that complete- 

 ness and authority which can alone make a laboratory 

 guide really useful. But the chapter on practical micro- 

 scopy is a really valuable one, giving the matured con- 

 clusions of the editor as to the true methods of getting 

 the best possible performance from the instrument. The 

 English school of microscopists is unrivalled in the 

 services which it has rendered to the development of 

 the microscope as an instrument of precision, and in the 

 cultivation of the art of obtaining from it the most 

 perfect optical results by skilful management of illumina- 

 tion, &c., as also of rightly judging and correcting those 

 results. The high eulogy passed on the Royal Micro- 

 scopical Society (p. 340), in view of its services in this- 

 field, is amply warranted. It is, however, to be regretted 

 that the name of the late Dr. Royston Pigott, F.R.S., is 

 omitted from the history here given of the improvements 

 in condensers, objectives, and eye-pieces. His valuable 

 contributions to the subject were rejected by the Society 

 in 1870, and published in the Quarterly Journal of 

 Mic7-oscopical Science at that period. 



The last three treatises are what give the book its 

 strange and almost incomprehensible character. There 

 can be no doubt that Prof. Bell would have written an 

 excellent original treatise on microscopic animals, and 

 Mr. Bennett an equally valuable one on microscopic 

 plants : but they have not been asked to do this. They 

 and others, and the editor himself, have contributed 

 fragments which are mixed up with fragments of the 

 original Carpenter in inextricable confusion. 



The "Author," with his capital A, appears as of old ^. 

 but he will now receive credit for opinions he never held, 

 and would probably have rejected. The present editor 

 is, however, careful to take responsibility himself for a 

 very rfemarkable statement — namely, that the saprophytic 

 Monadinai (such as Monas Dallingeri of Sav. Kent 

 and others) 



" possess features that ally them to the vegetable series, . 

 and indicate affinities with certain NostocaceJE and the 

 Bacteria ; while a leaning to the Mycetozoa [already 

 classed by our editor among Fungi !] and the chloro- 

 phyllaceous Algae, and even some forms of Fungi, is quite 

 apparent to the careful student." 



It is somewhat startling at the present day to come 

 across conceptions of this kind — groups " leaning" this 

 way and that, with remote affinities to half-a-dozen in- 

 compatible ancestries. One would like to know in 

 plain English whether Dr. Dallinger considers that the 

 Monadinae have descended from Nostocaceae, or from 

 Mycetozoa, or from green Algas, or any of the latter from 

 any of the former, or all from a common ancestor ; and 

 what grounds he has for his view as to their genealogy. 



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