Notices respecting New Books. . ~ 141 
fluid with calorie and light: but for the reasoning by which he 
supports this opinion we must refer our readers to the work it- 
self. 
Under the title “ Conciusion,” the author proceeds to con- 
sider the “ effects of magnetism, which bear so near a resem- 
bjance to those of electricity, as to leave little doubt that the 
causes must be very similar.”’ The explanations offered, assume 
that there are two ethereal fluids—as in electricity—inferred 
from *¢ incontrovertible experiment.” 
The following works have just been published: 
The Principles and Application of Imaginary Quantities; to 
which is added some Observations on Porisms, being the first of 
a Series of original Tracts on various Parts of the Mathematics. 
By Benjamin Gompertz, esq. 
An unlimited Daily Calendar, serving for every year, before 
and after the Christian zra, both for the old and new styles. By 
J. Garnett. 
A Treatise, containing the results of numerous experiments 
on the preservation of timber from premature decay, and on the 
prevention of the progress of rottenness, when already com- 
menced in ships and buildings, and their protection from the 
ravages of the termite, or white ant; with remarks on the means 
of preserving wooden jetties and bridges from destruction by 
worms. By William Chapman, M.R.I.A. Civil Engineer, &c. 
Mr. Thomas Forster has just published a Sixth Edition of his 
Observations on the Natural History and Brumal Retreat of the 
Swallow ; illustrated by fine engravings on wood, by Willis, and 
interspersed with Anecdotes. ‘To which is added Extracts from 
a Journal of Natural History, and a Catalogue of Birds which are 
found in the Island of Great Britain. 
He has likewise published Observations on the Casual and 
Periodical Influence of Atmospherical Causes on the Human 
Health, and Diseases, particularly Insanity; with a Table of Re- 
ference to Authors who have written on Epidemical and Periodi- 
cal Diseases. This work is illustrated by some novel cases, and 
the author endeavours to place the periods of insanity and other 
disorders of the brain and nervous system in the most insportant 
point of view, from the necessity of beginning the curative pro- 
ceeding at particular stages of the disorder. He classes the at- 
mospherical influence into two sorts: 1. That which appears 
casual or happens at uncertain periods, exciting epidemics and 
other atmospherical complaints. 2. That which has observ- 
able periods: — this he subdivides into annual, monthly, and 
daily periods. He notices also certain other periods which be- 
Jong exclusively to particular diseases. The tracts interspersed 
with 
