They've replaced the chemical solution with dry cells filled with chemical paste.

他们用充满化学粘浆的干电池取代了化学溶液。

We put them on our bodies and even our faces. Other chemical products are used throughout our homes.

我们用它们来洗身体，甚至洗脸。其他的化学品用在家里的方方面面。

Oxygen wasn't discovered until the 1770s, so early chemists had a different substance to explain how combustion worked.

氧直到 17 世纪 70 年代才被，所以早期化学家用不同的物质来解释燃烧如何工作的。

In the very next lecture, the professor taught that for viral diseases, chemically treated virus wouldn't do the trick.

在接下来的一节课，告诉他们，对于病毒性疾病来说，用化学方法处理的病毒行不通的。

They've replaced the chemical solution with dry cells filled with chemical paste, but the principle is the same.

他们用充满化学膏的干电池代替了化学溶液，但原理一样的。

Yeah, oh, I wanted to check the chemicals we used in the lab when we analysed those samples — was it potassium chromate and silver nitrate?

没错。对了，我想确认一下在实验室分析那些样品时使用的化学制剂，我们用的铬酸钾和硝酸银，对吗？

Well, if it isn't sweetened with real sugar, a lot of times it's sweetened with chemically derived additives that can be not so good for your health.

好吧，如果它不用真正的糖来增甜，那么很多时候它用化学衍生的添加剂来增甜的，这些添加剂可能对您的健康不利。

So the answer is not to make a spacecraft out of a flashlight, by having the exhaust come out this way and the spacecraft goes that way -- that's what we do today with chemistry.

所以答案不用手电筒制造航天器，让废气从这边出来， 然后航天器朝那边走——这就我们今天用化学所做的事情。