Sweat or Perspire- What is the difference between them ?

Sweat or Perspire

There is an old saying:

Horses sweat, men perspire, and ladies glow.

I had been reading a book where I found that the author used the word perspire for human being and the word sweat for animals, like horses. So I decided to google, then I found an old saying "horses sweat, men perspire" means sweat is used for animals and perspire is used for human. The information I found  provokes me to write this post including all the things that I found learning about these words.

"Horses Sweat; Men Perspire"

What is the meaning of sweat and perspire ?
Sweat and perspire mean the same thing to produce drops of liquid on the surface of your skin when you are ill, hot, or afraid.

Origin:
Perspire comes from the Latin "per spirare", meaning "to breathe through", in this case it means "the skin breathes by vapor".
Sweat comes from the Old English word "Swat".

What is the difference between Sweat and Perspire ?
Sweat seems to be a biological word, as it means producing liquid from sweat gland an internal part of a body to skin an outer part of a body.
Perspire, as it etymology suggests, works on outer part of the body, i.e, skin. Perspire means to vaporize water on skin.
Perspire is polite word for sweat.
Perspire is more formal word than sweat.
                                          In general sense, there is no difference between them. Both of them mean drops of liquid that form on your skin when you are hot. Sweat, however, more biological and informal words than perspiration. 
                                          In old days, as the saying pervades, "Horses sweat, men perspire", people used sweat for animals and perspire for human being. Present days, people more use sweat than perspiration. In old days, It was considered impolite to point out that somebody was sweating. That is why, people would use more polite word, i.e, perspiration in place of the word sweat.

What Reference Handbook of Grammar says:

The once-popular distinction between these words "Horses sweat; men perspire"- is not now generally observed. In fact, many people prefer the simpler, more direct word sweat to its polite substitutes perspire and perspiration, and always use sweat except in situations where it might offend more sensitive people (as in commercials for deodorants, where even the word perspiration is often avoided).

Here is what google suggests about the word usages over the time-

What people are saying:

In a Nutshell

You can use either of them. There is literally no difference; people are using sweat more often. 
Pointing out someone that he or she is sweating marks as impolite. If someone wants to be polite use the word perspire in place of sweat.

Prev. Post || Next Post

I have read some fantastic books on English language that really helped me improve my writing. You can buy my recommended books on Amazon. Here is the lists below:

Books on Grammar:

Books	Buy Links	Rating
The Elephants Of Style		4.5/5
English Grammar in Use Book		4.5/5
Practical English Usage		4.5/5
The Elements of Style		4.5/5
Essentials of English		4.5/5
Handbook of English Grammar and Usage		4.5/5
Woe Is I		4.5/5
Grammar Girl's Quick and Dirty Tips for Better Writing		4.5/5
It was the best of sentences, it was the worst of sentences.		4.5/5
If you want more books on English language, click the link