Book II Chapter 37

Use of a Loadstone as it affects iron.

B y magnetick coition we test iron ore in a blacksmith's forge. It is burnt, broken in pieces, washed and dried, in which way it lays down its alien humours; in the bits collected from the washing is placed a loadstone, which attracts the iron dust to itself; this, being brushed off with feathers, is received in a crucible¹, and the loadstone is again placed in the bits collected from the washing, and the dust wiped off, as long as any remains² which it will attract to itself. This is then heated in the crucible along with sal nitri187 until it is liquid, and from this a small mass of iron is cast. But if the loadstone draws the dust to itself quickly and readily, we conjecture³ that the iron ore is rich; if slowly, poor; if it seems altogether to reject it, there is very little iron in it or none at all. In like manner iron dust can be separated from another metal. Many tricks there are also, when iron is secretly applied⁴ to lighter⁵ bodies, and, being attracted by the motion of a loadstone which is kept out of sight, causes movements which are amazing to those who do not know the cause. Very many such indeed every ingenious mechanician will perform by sleight⁶ of hand, as if by incantations and jugglery188.

1 crucible   

n.坩锅，严酷的考验

参考例句：

• The alliance had been forged in the crucible of war.这个联盟经受了战争的严峻考验。
• Put the required amount of metal into the crucible.把适量的金属放入坩埚。

2 remains   

n.剩余物，残留物；遗体，遗迹

参考例句：

• He ate the remains of food hungrily.他狼吞虎咽地吃剩余的食物。
• The remains of the meal were fed to the dog.残羹剩饭喂狗了。

3 conjecture   

n./v.推测，猜测

参考例句：

• She felt it no use to conjecture his motives.她觉得猜想他的动机是没有用的。
• This conjecture is not supported by any real evidence.这种推测未被任何确切的证据所证实。

4 applied   

adj.应用的；v.应用，适用

参考例句：

• She plans to take a course in applied linguistics.她打算学习应用语言学课程。
• This cream is best applied to the face at night.这种乳霜最好晚上擦脸用。

5 lighter   

n.打火机，点火器；驳船；v.用驳船运送；light的比较级

参考例句：

• The portrait was touched up so as to make it lighter.这张画经过润色，色调明朗了一些。
• The lighter works off the car battery.引燃器利用汽车蓄电池打火。

6 sleight   

n.技巧，花招

参考例句：

• With a little statistical sleight of hand they could make things look all right.只要在统计上耍些小小的花招，他们就能瞒天过海。
• In the theater of the media there is an economic sleight of hand.传播媒介在经济上耍了一个大花招。