267 
i88o.] Analyses of Books . 
iron balustrades, bells, iron cramps and leadwork used in securing 
the masonry of spires and pinnacles, safes, machinery, &c. All 
such objects, the author shows, should be united in one metallic 
system, so that wherever the lightning may fall it may find a 
direct path down into the ground. In this last respect, also, too 
many conductors are faulty. The rods, wire-ropes, &c., often 
dip merely a few inches into earth which may become dry, and 
consequently non-conductive. il The earth-connection, Mr. 
Anderson declares, u is the alpha and omega of lightning pro- 
tection.” Further, a conduftor originally perfeft may be rendered 
useless by corrosion, or by damage inflicted by careless workmen. 
Hence these appliances should be subjected to an occasional in- 
spection, and their conductivity tested by means with which every 
electrician is well acquainted. # 
These lessons are enforced by practical examples, in which 
the damage or destruction of buildings supposed to be protected 
is explained by some deviation from the principles above laid 
down. 
An interesting feature of the work is a catalogue of public 
buildings struck by lightning from 1589 September, 1879? an d 
of twenty-four cases of the explosions of powder magazines 
from the same cause. One of these, at Brescia, in August, 
1769, proved fatal to three thousand persons. There, is also a 
very elaborate bibliography of the subject from Hieronymus 
Cardanus downwards. 
The book is plentifully illustrated, and will prove a most valu- 
able guide to engineers, architects, builders, and to all persons 
entrusted with the care of public buildings, magazines, ship- 
ping, &c. 
Proceedings of the Birmingham Philosophical Society . 1878-79. 
Vol. i., No. 3. Birmingham : Corns, Sheriff, and Rattey. 
This volume is very much more valuable and satisfactory than 
the average proceedings of our provincial learned Societies, and 
Birmingham has fair reason to feel proud of the result. The 
simple fact is that we find here a very fair proportion of actual 
sterling scientific work instead of mere words and dreams. 
Dr. Norris’s paper on the “ Development of Mammalian 
Blood” is exceedingly interesting. He finds that there exist in 
mammalian blood numerous corpuscles incapable of being seen 
by the microscope — not from their minuteness, but because they 
have the same refractive index and colour as the liquor sanguinis 
in which they float. They are colourless biconcave disks, be- 
tween which and the red biconcave disks other corpuscles can 
be detected possessing every gradation of tint. The morpholo- 
