267 
i 877 *j Notices of Books. 
of attributing the same action to the pistons of brass instru- 
ments which do not open holes in the tube, but by means of 
valves add additional lengths of pipe, and so produce different 
fundamental notes, the harmonics of which are formed by the 
lips and pressure of breath of the performer. 
Fuller information respecting the structure of musical instru- 
ments would have been very acceptable to a large class of 
readers, especially as information on this subjeCt is not easily 
attainable. 
Several chapters are devoted to subjects almost entirely mu- 
sical, such as ratios, consonant and dissonant chords. The 
nature of scales, ancient and modern, is explained in consider- 
able detail. The “ Equal Temperament ” does not find much 
favour with Prof. Blaserna : he accepts it as a necessary evil, 
but considers that a key-board of twenty-four notes to the oCtave 
would just be able to produce a satisfactory effeCL 
The chapter on Timbre, or quality of sounds, is particularly 
interesting, and contains descriptions of the Phonauto graph of 
Scott, and the equally valuable Harmonic Detector of Konig. 
Histological Demonstrations, being the Substance of Lectures 
delivered by George Harley, M.D., F.R.S. Edited by 
George T. Brown, M.R.C.V.S. Second Edition. London: 
Longmans and Co. 
Works containing the practice of accomplished manipulators 
in any branch of Science are always welcome, and the present 
little book is no exception. The carefully edited notes of 
Mr. Brown have in this edition had the advantage of Professor 
Harley’s revision, and the result is a collection of practical in- 
formation of the utmost value to medical and veterinary 
students. 
The portion of the work devoted to the description of the 
instrument, its use, and the general processes employed in the 
preparation of tissues for microscopical examination, is some- 
what small, only twenty-seven pages being devoted to these 
subjects ; however, this department has been so fully treated in 
the copious works of Beale, Carpenter, and others, that greater 
extension was hardly needed, and more space has been left for 
the special subject of the work. 
Of the treatment of this part it is hardly possible to speak too 
highly. 
The tissues, from the most elementary to those of the highest 
elaboration, are described briefly, yet with sufficiency of detail 
to aid the student ; special directions are given as to the best 
mode of manipulating, and a diagram or figure given with each, 
to call attention to what should be observed ; no less than two 
