226 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
designs, and is intended to obviate tbe many difficulties incident to the 
fixing of tbe dishes on ordinary Microscope stages. The designer con- 
siders that a satisfactory holder should be capable of the three following 
motions : — (1) a radial push-motion ; (2) a rotation ; (3) a central 
lateral movement of at least 5 mm. in each direction, apart from the due 
centering of the culture layer. Fig. 58 shows how these requirements 
were perfectly attained. On a liollowed-out piece F, fastened by two 
screws V Y x to the prism flange of the Microscope, there extend antler- 
wise two bent arms A A x . The extremity of A x carries a threaded socket 
L, and the extremity of A is arranged for the adjustment. L receives the 
Fig. 58. 
axle B, which is firmly clamped by the tightening of the screw K. The 
centering arrangement C consists of a brass block with a double concave 
perforation ( in long, section), whose least cross-section receives the axle 
B without loose play. The axle B is interrupted in its midst by a ring 
arrangement R, formed of an inner and an outer part. The outer simple 
ring is of cylindrical cross-section, and its inner diameter about 105 mm. 
Within this ring (milled) is a second, much thinner, fitted with three 
clamps HF 1} HF 2 , HF 3 , tipped with cork or vulcanite, for reception of 
the d sh. 
When in use the ring arrangement R lies flat on the object-table. 
Spitta’s Photomicrography.* — This work, published by the ‘ Scien- 
tific Press,’ is mainly a reprint of the articles which recently appeared 
in the ‘Pharmaceutical Journal’ and were abstracted in this Journal. f 
The book is got up attractively, with forty-one half-tone reproductions 
and sixty-three text illustrations. The size is a large quarto, and some 
useful appendices are inserted. All theoretical discussion has been 
avoided, with the hope of producing a practical manual, the embodiment 
of the author’s experience. The half-tone reproductions are the work 
of Messrs. Dent and Co., of Clapkam. 
* London, Scientific Press (Lim.), 1899, 4to, 163 pp. 
t Cf. this Journal, 1898, p. 591. 
