Useful Knowledge
章节目录
共 21 段- 22. It is one of the most remarkable properties of oxygen to
- Mr. Mawe remarks that diamonds, when rubbed together, have a
- By the ancients the emerald was a gem much in request, and p
- These stones are considered by some writers as varieties of
- 102. _OPALS are a semi─transparent kind of stones, which hav
- 119. _TRIPOLI is a kind of clay of yellowish grey, brown, or
- From the roughness and tenacity of this stone, in addition t
- 144. GREEK WHITE MARBLE.—_The Marmo Greco, of Italian artist
- _They have their names from the places where they are respec
- This alkali is of essential use in the arts. When melted wit
- Sal─ammoniac is applied to many useful purposes. Occasionall
- Coals are principally obtained from the neighbourhood of
- It has already been mentioned that insects are occasionally
- By means of mercury a _fulminating powder_ is made, which, w
- In its appearance, malachite somewhat resembles green jasper
- The article usually called _tin_, or _tin─plate_, and, in Sc
- Of all substances with which we are acquainted this is perha
- The royal summer garden at Petersburg is decorated with a su
- The _chemical analysis of water_, for the purpose of ascerta
- Wherever a large quantity of this water passes hot from the
- The common people so much esteem this water that many of the