120 Notices of Books. [January, 



describe practically the methods of mounting objects dry, in 

 balsam and solution of damar, and in fluids. The system of 

 selecting a list of typical and easily procured objects is a good 

 one : each object so selected is treated separately, and by fol- 

 lowing out the processes described in these chapters the student 

 who is deprived of the help of more experienced workers will be 

 able to make considerable progress. The author is evidently too 

 fond of the old method of potass maceration in making prepara- 

 tions of insects. The flea as prepared by him is the mere empty 

 skin so common in cabinets : this has only to be compared with 

 specimens mounted in glycerine, without compression, with the 

 contents of the body in situ, to cause it to be abandoned, ex- 

 cepting in those cases where the chitinous tissues alone are 

 required. The proboscis of the blow-fly, again, is so treated as 

 to produce the common preparation of the shops, — a mode of 

 mounting which has for years only served to prevent a true 

 knowledge of the structure of this wonderfully complex organ 

 from being obtained. The author has surely never seen some 

 of the insect preparations au naturel, which "are now far from 

 uncommon in the cabinets of some of our best microscopists. 



A great deal of useful information is contained in chapter 5, 

 giving a general summary of various modes of mounting. A 

 large number of interesting objects are here described, and 

 directions given for their examination. 



The chapter on Collection gives a great many hints for cap- 

 turing the small game so much sought after by the microscopist. 



Some notice is taken of the important subject of adulterations, 

 but the treatment is so brief — giving little more than a catalogue 

 of adulterating substances — that the information will prove of 

 but little use to the reader. At page 167 the author gives a 

 figure of " a precipitating cell " of his own contrivance, but has 

 unfortunately left out all description, so that the reader is left to 

 make out what he can from the woodcut. 



The appendix is one of the most useful portions of the book, 

 containing no less than seventy-seven formulas for various ce- 

 ments, mounting media, reagents, &c. This microscopic phar- 

 macopoeia, compiled from various sources, supplies a real want, 

 and will be duly appreciated. 



With regard to the illustrations, the author has certainly not 

 improved in his lithography since the issue of his work on 

 " Microscopic Objects." This is much to be regretted, as Plate 

 11 — a reproduction of some of the author's drawings by the 

 photo-lithographic process — shows that the defect is a want of 

 skiil in the manipulation of the lithographic materials. The 

 other plates are characterised by a general coarseness of execu- 

 tion. The figure of flax, PL 10, Fig. 92, is unlike any fibre 

 known to the histologist, and the whole plate is a specimen of 

 very coarse wood-engraving. It is a pity that the book should 

 have been spoiled by the bad execution of so important a portion. 



