Or, what would put it in simpler form to an uninitiated guest, he is apparently first charged for the raw provisions he consumes, and for the rent of his bed- room.

This is the proprietor's share.

Then, there is a separate charge for each of the remaining items of the entertainment,--for cooking and serving up each meal, for making up your bed, and for blacking your boots; just as distinctly as if you had gone out into the town the previous evening and hired three separate individuals to perform these services for you; and as if you had no right nor reason to expect from the landlord a dinner all cooked and served, but that you only bought it in the larder.
Now, this is a peculiarity of the English hotel system that is apt to embarrass travellers from other countries, especially from America, where no such custom could be introduced.

I do not know how old the custom is in Great Britain.

Doubtless it originated in the almost universal disposition and habit of Englishmen of dropping gratuities or charity-gifts here and there with liberal hand, either to obtain or reward extra service in matters of personal comfort, or to alleviate some case of actual or stimulated suffering that meets them.