Book II chapter 29

On Variety of Strength due to Quantity or Mass.

Q uite similar in potency¹ are those stones which are of the same mine, and not corrupted² by adjacent ores or veins³. Nevertheless that which excels in size shows greater powers, since it seizes greater weights and has a wider orbe of virtue⁴. For a loadstone weighing one ounce does not lift a large nail as does one weighing a pound, nor does it rule so widely, nor extend its forces; and if from a loadstone of a pound weight a portion is taken away, something of its power will be seen to go also; for when a portion is abstracted the virtue is lessened⁵. But if that part is properly applied⁶ and united to it, though it is not fastened to nor grown into it, yet by the application it obtains its pristine⁷ power and its vigour⁸ returns. Sometimes, however, when a part is taken away, the virtue turns out to be stronger on account of the bad shape of the stone, namely, when the vigour is scattered⁹ through inconvenient¹⁰ angles. In various species the ratio is various, for one stone of a drachm weight draws more than another of twenty pounds. Since in very many the influence is so effete¹¹ that it can hardly be perceived, those weak stones are surpassed by prepared pieces of clay. But, it may be asked179, if a stone of the same species and goodness weighing a drachm would seize upon a drachm of iron, would a stone of an ounce weight seize on an ounce, a pound on a pound, and so on? And this is indeed true; for it both strains and remits¹² its strength proportionately, so that if a loadstone, one drachm of which would attract one drachm of iron, were in equal proportion applied either to a suitably large obelisk¹³ or to an immense pyramid of iron, it would lift it directly in such proportion and would draw it towards itself with no greater effort of its nature or trouble than a loadstone of a drachm weight embraces a drachm. But in all such experiments as this let the vigour of the magnets be equal; let there be also a just proportion in all of the shapes of the stones, and let the shape of the iron to be attracted be the same, and the goodness of the metal, and let the position of the poles of the loadstones be most exact. This is also no less true in the case of an armed loadstone than of an unarmed one. For the sake of experiment, let there be given a loadstone of eight ounces weight, which when armed lifts twelve ounces of iron; if you cut off from that loadstone a certain portion, which when it has been reduced to the shape of the former whole one is then only of two ounces, such a loadstone armed lifts a piece of iron applied to it of three ounces, in proportion to the mass. In this experiment also the piece of iron of three ounces ought to have the same shape as the former one of twelve ounces; if that rose up into a cone¹⁴, it is necessary that this also in the ratio of its mass should be given a pyramidal shape proportioned to the former.

1 potency   

n. 效力，潜能

参考例句：

• Alcohol increases the drug's potency.酒精能增加这种毒品的效力。
• Sunscreen can lose its potency if left over winter in the bathroom cabinet.如果把防晒霜在盥洗室的壁橱里放一个冬天，就有可能失效。

2 corrupted   

（使）败坏( corrupt的过去式和过去分词 )； （使）腐化； 引起（计算机文件等的）错误； 破坏

参考例句：

• The body corrupted quite quickly. 尸体很快腐烂了。
• The text was corrupted by careless copyists. 原文因抄写员粗心而有讹误。

3 veins   

n.纹理；矿脉( vein的名词复数 )；静脉；叶脉；纹理

参考例句：

• The blood flows from the capillaries back into the veins. 血从毛细血管流回静脉。 来自《简明英汉词典》
• I felt a pleasant glow in all my veins from the wine. 喝过酒后我浑身的血都热烘烘的，感到很舒服。 来自《简明英汉词典》

4 virtue   

n.德行，美德；贞操；优点；功效，效力

参考例句：

• He was considered to be a paragon of virtue.他被认为是品德尽善尽美的典范。
• You need to decorate your mind with virtue.你应该用德行美化心灵。

5 lessened   

减少的，减弱的

参考例句：

• Listening to the speech through an interpreter lessened its impact somewhat. 演讲辞通过翻译的嘴说出来，多少削弱了演讲的力量。
• The flight to suburbia lessened the number of middle-class families living within the city. 随着迁往郊外的风行，住在城内的中产家庭减少了。

6 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。

7 pristine   

adj.原来的，古时的，原始的，纯净的，无垢的

参考例句：

• He wiped his fingers on his pristine handkerchief.他用他那块洁净的手帕擦手指。
• He wasn't about to blemish that pristine record.他本不想去玷污那清白的过去。

8 vigour   

（=vigor）n.智力，体力，精力

参考例句：

• She is full of vigour and enthusiasm.她有热情，有朝气。
• At 40,he was in his prime and full of vigour.他40岁时正年富力强。

9 scattered   

adj.分散的，稀疏的；散步的；疏疏落落的

参考例句：

• Gathering up his scattered papers,he pushed them into his case.他把散乱的文件收拾起来，塞进文件夹里。

10 inconvenient   

adj.不方便的，令人感到麻烦的

参考例句：

• You have come at a very inconvenient time.你来得最不适时。
• Will it be inconvenient for him to attend that meeting?他参加那次会议会不方便吗？

11 effete   

adj.无生产力的，虚弱的

参考例句：

• People said the aristocracy was effete.人们说贵族阶级已是日薄西山了。
• During the ages,Greek civilization declined and became effete.在中世纪期间，希腊文明开始衰落直至衰败。

12 remits   

n.职权范围，控制范围，影响范围( remit的名词复数 )v.免除（债务），宽恕( remit的第三人称单数 )；使某事缓和；寄回，传送

参考例句：

• He remits home every month. 他每月汇款回家。 来自《现代汉英综合大词典》
• Second, company remits are far more global than that of the average job seeker or sovereign. 其次，较之普通求职者或一国政府，企业的活动要全球化得多。 来自互联网

13 obelisk   

n.方尖塔

参考例句：

• The obelisk was built in memory of those who died for their country.这座方尖塔是为了纪念那些为祖国献身的人而建造的。
• Far away on the last spur,there was a glittering obelisk.远处，在最后一个山峦上闪烁着一个方尖塔。

14 cone   

n.圆锥体，圆锥形东西，球果

参考例句：

• Saw-dust piled up in a great cone.锯屑堆积如山。
• The police have sectioned off part of the road with traffic cone.警察用锥形路标把部分路面分隔开来。