On Subtlety

Why things heard delight more than things read. — 291
Oat water intoxicates. see Intoxicating drink.
Why there are more nocturnal birds than four-footed animals. — 233
Why birds lack teeth and a bladder, but have a small head and two stomachs. — 244
Tame birds. — 244
How birds are captured. — 288
An abundance of birds of every kind is evidence of the healthiness of the air. see Air.
The largest bird. — 241
How growth original: "Augumentum" occurs. — 265
The form of Augustus. — 260
The double privilege of the ears. — 277
The incredible size of pure gold. — 148 original: "Auri obrizi". Obryzum refers to gold that has been refined and tested for purity by fire.
All the privileges of gold. — 151
The method of purifying gold. — 152
The thinness of gold in leaves. — 151
The wondrous thinness of gold and silver. — 150
How gold is generated. — 147
How gold is found. — 147
Gold is obtained in three ways. — 148
Gold more perfect than gold. — 152
Gold yields least of all to fire. — 151
How gold is collected in fragments. — 139
How gold is separated from other metals. — 152
Gold and silver are contained in all metals. — 152
Whether gold is attracted. see Kite-fish. original: "Miluini piscis". This likely refers to a belief that certain fish or stones could attract metals.
How gold is separated from silver. see Water of separation. original: "Aqua separationis," an early term for nitric acid used in assaying.
Why gold and gems abound more in the East and South than elsewhere. — 121
Gold alone is submerged in quicksilver. — 138
Gold smeared with quicksilver is broken. — 139
Gold smeared with quicksilver is fouled. see Quicksilver.
Brass original: "Aurichalcum". Historically, this refers to a gold-colored alloy, usually brass or a similar copper alloy. and its composition. — 259
The most noble brass. — 160
Orpiment. — 137 original: "Auripigmentum". A deep orange-yellow arsenic sulfide mineral used as a pigment.
Cooked orpiment. — 142
The greatest stars of the Southern Pole. — 86
Of the authors who wrote about demons. see Those who have touched upon the history of demons.
The subtlety of authors of seven kinds. see Subtlety of authors.
The greatest [works] of individual authors. — 315
The author was warned in a dream to compose these books. — 356
The wondrous history of the author. — 357
The author's ancestors were of long life. — 261

Whale. see Great sea monsters. original: "Cete".
The structure of ballistae. see Structure of scorpions. Scorpions were ancient heavy-duty crossbow-like siege engines.
Why balsam is watered from a single well. — 337
The powers of true balsam. — 204
Indian balsam. — 204
Belemnite stone. — 192 A fossilized internal shell of an extinct cephalopod, often called "thunderbolts" in folk tradition.
Engines of war. see Fiery engines.
Engines of war strike according to the order of the universe. see War engines.
Benzoin. — 198 original: "Belzoi". A balsamic resin from trees in East Asia.
The Bialozor bird. — 241 A term used in older texts for the Gyrfalcon or a great hawk.
Beer. see Zythum. Zythum was a type of ancient Egyptian beer.
Jewish bitumen. see Asphalt.
Twelve noble kinds of bitumen. — 131
Cockroaches or moths. — 225
How the moths of clothes may be removed. see Of clothes.
Cannons. see Fiery engines. original: "Bombardæ".
Silkworms known to Aristotle. — 222
Good things are inferior to bad things. see Bad things.
The end of good things is freedom from pain. — 370
Borax stone. — 183
The North original: "Boreas" abounds in metals, the South in gems. see South.
Oxen. see Cows.
The protruding tongue of an ox twitches for a long time. — 245
Why the broth of beef is more succulent than that of veal. see Broth of beef.
The method for the foils original: "Bractearum" which are placed under gems. — 160
Brazilwood. — 209 original: "Brasilium". A wood used for red dye.
Britain abounds in crows. — 227
Why Britain lacks snakes. — 227
Praise and wonders of Britain. — 227
Broth. see Juice. original: "Brodium... l. Ius".
The power of the toad. — 351 original: "Buffonis".
Buprestis. see Spanish flies. A type of beetle believed to be toxic to cattle if swallowed.