eggnog [cocktail] that was once popular." The Tom and Jerry was invented by British journalist Pierce Egan in the 1820s, using brandy and rum added to eggnog and served hot, usually in a mug or a bowl. It is a traditional Christmastime cocktail in the United States. Isaac Weld, Junior, in his book Travels Through the States of North America and the Provinces of Upper and Lower Canada, during the years 1795, 1796, and 1797 (published in 1800) wrote: "The American travelers, before they pursued their journey, took a hearty draught each, according to custom, of egg-nog, a mixture composed of new milk, eggs, rum, and sugar, beat up together". In a similar way to how posset was drunk as a cold remedy in the Medieval era, there is evidence that eggnog was also used as a medical treatment. An 1892 scientific journal article proposes the use of eggnog to treat "grippe", commonly known as the "flu", along with ammonium chloride to treat the cough and quinine to cure the illness. In the American South, eggnog is made with bourbon. Eggnog is called "coquito" in Puerto Rico, where rum and fresh coconut juice or coconut milk are used in its preparation. Mexican eggnog, also known as "rompope", was developed in Santa Clara. It differs from regular eggnog in its use of Mexican cinnamon and rum or grain alcohol. In Peru, eggnog is called "biblia con pisco", and it is made with a Peruvian pomace brandy called pisco. German eggnog, called "biersuppe", is made with beer. "Eierpunsch" is a German version of eggnog made with white wine, eggs, sugar, cloves, tea, lemon or lime juice and cinnamon. Another recipe dating from 1904 calls for eggs, lemon juice, sugar, white wine, water and rum. In Iceland, eggnog "is served hot as a dessert." Ingredients and serving style Homemade Traditional homemade eggnog is made of milk or cream, sugar, raw eggs, one or more alcoholic spirits, and spices, often vanilla or nutmeg and in some recipes, cloves. Some recipes call for the eggs to be separated so that the egg whites can be whipped until they are thick; this gives the drink a frothy texture. American food show presenter Alton Brown points out that based on its ingredients, eggnog is "almost identical to ice cream. It is technically just a stirred custard made of milk and egg". Homemade recipes may use vanilla ice