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POPULAR SCIENCE REVIEW. 
•which, lives in a sort of suspension home : — “ A peculiarly beautiful pensile 
cocoon is constructed by a common British spider, scientifically termed 
Agelena brunnea. The cocoon is shaped rather like a wine-glass, and is 
always hung with the mouth downwards, being fastened by the stalk to a leaf 
or twig of gorse. It is very small, only measuring a quarter-of-an-inch in 
diameter, and when it is first made is of the purest white.” We wish we 
had space to follow the writer in his descriptions of the nest-building habits 
of the sticklebacks, and of the homes of the beaver, the dormouse, and the 
bee. Pressure on our pages forbids our doing more than commending the 
volume to the attention of our readers, and assuring them that it will repay 
a careful perusal. 
IRON SHIP-BUILDING* 
I N this book the author enters upon all the technical bearings of his- 
subject, and yet has not surrounded his remarks by difficulties which 
cannot be overcome by any ordinarily intelligent reader. The portion of 
the book most interesting to the general public is that concerning the- 
relative values of iron and wood in the construction of vessels of war. Mr. 
Fairbairn, though a well-known and enthusiastic advocate of the use of iron, 
in all forms of architecture, does not approve of vessels of such construction 
as the Warrior. He shows in the clearest manner that if we would build 
vessels capable of resisting our present ordnance, we should make 
them of such a thickness and bulk that they could not be managed in any 
but the calmest waters. He proposes not to dispense entirely with the 
armour-plates, but to apply them with careful attention to the more vulne- 
rable parts of the ship, so as not to injure her sailing powers and other 
conditions necessary to the attainment of speed. This he thinks can be 
effected by a simple belt of plating, eight feet deep, that is four feet above 
and four below the line of floatation. We believe Mr. Fairbairn’s suggestion 
is being carried out by the Admiralty, who are building, or intend to build 
four vessels plated upon the above plan ; or, as Lord Clarence Paget calls, 
them, “ an improved class of Alabamas 
MODERN CHEMISTRY.j- 
D URING the last thirty years the science of Chemistry has been under- 
going serious transformations. It has thrown off the shackles of 
hypothetical doctrines, and has burst the prison-walls of vague speculation. 
To-day it is no longer a collection of dry facts and ill-supported explanations* 
but is qualified to range amongst the exact sciences. Chemists of the present 
* u Treatise on Iron Ship-building : its History and Progress.” By W. 
Fairbairn, C.E., F.R.S. Longmans & Co. 1865. 
t “ Introduction to Modern Chemistry, Experimental and Theoretic.” By 
A. W. Hofmann, LL.D., F.R.S. London : Walton & Maberly. 1865. 
