SCIENTIFIC NEWS. 
285 
SCIENTIFIC NEWS. 
A Treatise on new philosophical instruments for various 
purposes in the arts and sciences, with experiments on light 
and colours. By David Brewster, L L. D. F. R. S. E, &c. 
octavo 427 pages with 12 copper plates. Edinburgh printed 
1813, and sold also in London. 
The present notice will contain only a concise indication 
of the subjects contained in this valuable treatise. They 
all relate to optics and the properties of light, in five books, 
divided into chapters. The first book affords descriptions of 
the common micrometer, and seven new micrometers on 
different principles j viz. the wires, divided object glass, 
luminous image, mother of pearl, rotatory, eye-piece wire, 
and their applications. Book II. Instruments for measuring 
angles when the eye is not at their vertex. Book III. Instru- 
ments for measuring distances. Book IV. Instruments for view- 
ing objects under water : another for measuring the refractive 
powers of fluids, with a method of determining the refractive 
powers of solids ; another instrument for measuring the disper- 
sive and refractive powers of solid and fluid substances, with re- 
marks on the irrationality of the coloured spaces in different 
mediums ; new properties impressed upon light by transmission 
through diaphanous mediums, and by its reflection from po- 
lished surfaces, &c. Book V. New telescopes and microscopes. 
Experimental Researches concerning the Philosophy of 
Permanent Colours, and the best means of producing them 
1 by dyeing, calico printing, &c. By Edward Bancroft, M. D. 
j F. R.S. &c. in two volumes octavo, containing 1028 pages. 
besides 
