Old Maid and Whist are two classic card games. Old Maid is a Victorian game: the basic aim is to avoid being the player left holding the 'Old Maid', a card that will have been singled out at the beginning (usually the ace of spades, queen of spades or joker).
Whist, another classic English card game, was popular in the 18th and 19th centuries. It's a trick-taking game, with more modernised versions known as trumps.
The word rachitic means that the man had the appearance of someone with rickets, a disease resulting from a lack of vitamin D or calcium and from insufficient exposure to sunlight. It is characterised by defective bone growth.
Siwash can be an offensive term for a North American Indian, but here it refers to a camp made without a tent or any proper supplies; living off the land and using only natural shelter.