ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 



f>23 



undue straining of the contact points, and is made in sizes to take £ in. to 

 1 in. measurement in steps of T1T Vo * a ' The pitch of the screw-shaft is 50 

 to the inch, and the circumference of the cylinder carried by the shaft 

 is divided into 20 parts, so that each division on the cylinder equals 



Fir.. 125. 



• 001 in. By slightly enlarging the cylinder, a reading of T tf<h> o * n ' 

 is obtained by subdividing the 20 divisions into 10 parts. These 

 gauges are also made to read in metric measure to 0*01 and 0*001 mm. 



Lee and Henneguy's Histological Technique.* — The well-known 

 treatise on the technique of microscopical anatomy by Bolles Lee and 

 Henneguy has reached its third edition. In the present issue the work 

 has been practically recast and is considerably enlarged. While 

 numerous obsolete methods have been omitted, fifty pages of entirely 

 new matter have been added. The additions include chapters on the 

 theory of fixation, setting of microtome knives, principles of histo- 

 logical staining, methods for making series of sections, &c. The 

 chapters on coal-tar colours and on cytological methods have been 

 practically re-written, and that on neurological methods has not only 

 been entirely recast but has been remodelled on a scheme suggested by 

 van Gehuchten. The authors acknowledge also assistance from P. Mayer 

 in the selection of new matter in the chapters on zoological methods. 



Dictionary of Photography.f — E. J. Wall's Dictionary of Photo- 

 graphy has just reached its eighth edition. The present issue, enlarged 

 to 656 pages, has been revised and brought up to date by T. Bolas. 

 Nearly 100 pages of new matter and many diagrams have been added, 

 but owing to concentration and elimination the bulk of the volume is 

 not unduly increased. The work presents the same general features as 

 have rendered its success so marked. 



Re-crystallisation of Platinum.} — W. Rosenhain points out that 

 platinum, when used as foil or as crucible, is in a condition of severe 

 strain, having been bent, drawn, rolled, &c. either in the cold or at 

 temperatures far below its annealing temperature. When submitted 

 to a prolonged exposure at a high temperature it undergoes re-crystal- 

 lisation, and then becomes brittle. 



* Traite des Methodes techniques de ll'Anatomie Microscopique, Histologic. 

 Ernbryologie et Zoologie, par A. Bolles Lee et L. F. Henneguy, avec une preface 

 par Prof. L. Ranvier, 3 me e'dition, Paris, Octave Doin, 1902, ix. and 553 pp. 



+ Hazell, Watson and Viney, London, 1902, fi56 pp. 



X Proc. Rov. Soc, lxx. No. 462 (1902) pp. 252-4 [l fig.). 



