Green’s Dictionary of Slang

Hollands n.

gin.

1755		Connoisseur in N&Q Ser. 7 X 78: Every night cellar will furnish you with Holland tape [gin] three yards a penny [F&H].
1844		Northern Star 13 Jan. 4/4: Sum of them runnin as mad at Orange as a bull at scarlet because king William [...] wanted to introduce Hollands instead of Wisky.
1856		J. Strang Glasgow and Its Clubs 422: Having each swallowed a bumper of Hollands, no doubt to inspire them with Dutch courage, they wheeled into Indian file.
1871		C. Money Knocking About in N.Z. 113: A bottle of Hollands, which was disposed of with the utmost celerity.
1884		Dundee Courier 26 Feb. 7/3: Look at that! Hollands, lad.
1890		Bird o’ Freedom 8 Jan. 1/4: Hot Scotch, hot rum, hot brandy, hot hollands, and even hot port.
1911		J. Masefield Everlasting Mercy 27: So round the gin went, hot and heady, / Hot Hollands punch on top of deady.