Why does Conrad refer to champagne as "medical comforts"? "Holding a half-pint champagne bottle (medical comforts) . . ."I am translating Heart Of...

What a great project! Any time we translate into another language there are metaphors and nuances that do not translate well.  Hence we say "something is lost in translation."

The idea of champagne or any alcoholic beverage being a comfort arose as a euphemism in English. A "euphemism" is a word or expression that allows us to express an idea in a way that we believe is not as embarrassing as an outright statement.  So, for example, one might use the word "bosom" instead of the word "breast," or speak of the "ladies' room" instead of referring to the room that has the toilet we need!  Euphemisms were particularly common in Victorian times, when people thought it somehow offensive to speak of sexual anatomy or bodily functions. But I must say that it is likely that all languages and periods have some euphemisms.

Now, having said all of that, many people in the past (and now) felt that consuming alcohol was shameful and weak.  Some people who wished to indulge in its use claimed that it was solely for "medicinal purposes."  This was supposed to make others think that the alcohol had been "prescribed" or advised by a physician and was not a weakness or indulgence on the speaker's part.  In fact, before alcohol and various drugs were regulated by government, many pharmaceutical concoctions contained alcohol or drugs that would be illegal today.

Today, we often use the term "medicinal purposes" somewhat ironically, to show that we know how foolish a euphemism this was.  In fact, I have said this myself on occasion, telling my husband that I was drinking a glass of wine for medicinal purposes only.  This has become a common joke in English for people who are aware of the history of this euphemism.  I suspect Conrad was using the expression he used as a bit of a joke, too, knowing that the reader knew full well that champagne served no medical use whatsoever! If he were speaking to us and said this, the comment would have likely to have been accompanied by a wink.

Are you aware that English was not Conrad's native language?  He was born in Ukraine, raised later in Poland, and did not learn English until he was an adult.  Born in 1857,he only  became a British citizen in 1886, having travelled all over the world as a seaman.  His mastery of English, evidenced in his wonderful novels, is truly amazing.

Good luck to you in your translation.