Scotch whisky and soda water is now considered one of the classic drinks of England and its kindred states. But it dates back only to about the 1880's and a break in the importing of French wines and brandies into England.
Naturally carbonated mineral waters had been known since antiquity - Hippocrates praises their medicinal value, for instance - but most alcoholic drinks were traditionally flat ("still") until the 17th century. Sparkling wines and carbonated ales and beers could be produced with consistent quality only after the development of the cork stopper and improvements in the making of strong-walled bottles after 1650. England certainly had a thirst for carbonated liquors early on. It is said that French wines were commonly refermented there, through the addition of yeast and sugar, in the early 1700's. Champagne as we know it, made in thick-walled bottles with fat corks, dates from 1757. (How glorious is the march of progress!) The artificial carbonation of still liquors, however, took much longer to develop, and seems only to have begun after the development of carbonated sweet drinks.
In 1715, the Dutch scientists Pieter van Musschenbroek (1692-1761) and Hermann Boerhaave (1668-1738) first isolated carbon dioxide, and showed that it was this gas that made sparkling waters sparkle. The 18th century saw great advances in the study of chemistry and the extraction of gases, and carbonation was a subject of lively interest. Not until 1767, however, did Joseph Priestley (1733-1804) succeed in producing an artificial carbonation process by dissolving carbon dioxide in plain water. Within a few years, Priestley's process had been streamlined by Torbern Bergman (1735-1784), and artificial soda waters began to compete with natural mineral waters.
These waters were flavored in various ways. By the beginning of the 19th century, "sweetwater" (flavored soda water sweetened just before drinking) had become a popular class of drinks. The process of carbonization was massively industrialized in the 1830's, and bottled carbonated soft drinks began to appear in the 1850's, beginning with ginger ale in Ireland and developing rapidly in the United States during Reconstruction. The nineteenth century was the age of carbonation.
But we were speaking of hard drinks. In the mid-Victorian period, brandy and soda was the drink of choice among the English middle classes. In the late 1870's, however, France (and particularly the Champagne region) was devasted by the phylloxera epidemic, and the supply of French brandy and Champagne virtually dried up. Scottish things were in vogue, and Englishmen seem to have turned to adding soda to scotch at this time. The heavy, dark single malts that had predominated until then began to be replaced by blends, which were lighter in color and quality, and more consistent from batch to batch. Whisky distillers had never marketed single malts by name and so had been under no pressure to maintain their consistency; consequently neat malt was a dark-colored, fairly harsh drink generally taken hot as toddy - mulled with spices, lemon, and other things the Scotch whisky industry no longer likes to talk about. (Take a look at Lagavulin if you want to see an authentic specimen of pre-blend Scotch.) But the new blends were marketed by brand names, many of them still familiar today. The development of blends and their combination with soda water seems to have led to a great improvement in the refinement of the drink of Scotch from the time of the phylloxera epidemic onward. (The epidemic also led to the modern French system of regional wine-naming controls.)
Scotch and soda was in great fashion in England and its possessions for some 20 years - the greatest generation of the British Empire - until a whisky glut around the turn of the century put many distillers out of business. Champagne came back into fashion among the upper classes, and has been their signature drink since the reign of Edward VII.
But we scotch and soda enthusiasts persist.