When making one’s way through another world’s jokes, something we do here as we examine the comic postcards of a century or half century ago, it us important not to get too judgy. Roger Ebert stated once that it is not a critic’s job to say “That’s not funny.” No one appointed the critic as the final arbiter on everything anyone ever wrote. The best he can say, according to Roger, is “That didn’t make ME laugh.”
So I try to steer clear of the word “offensive” when I am looking over postcards. Some jokes do strike me as offensive, but I try to remember the world of jokes includes people who like to swap offensive jokes. Besides, some jokes are offensive and funny. (Another reference here: Dorothy L. Sayers referred to what the old lady said to the young man: “Some people can be funny without being offensive and some can be both funny and offensive. I suggest you be one or the other.)
But I do run across postcards once in a while that make me stop and wonder. What I am wondering is either a. Would a publisher dare publish that today? Or b. How did a publisher dare publish that THEN? I HAVE found a few postcards which are clearly stamped that they must be enclosed in an envelope and not sent through the mail as is. For example, there is

But Mr. Goldring specialized in slightly off-color cartoons, and I’m not sure the post office would blench at this today, any more than they would care about this other one, (stamped “Not to Be Mailed”) in which a so-so cartoonist has repeated an old image of a man flushing himself down a toilet, saying “Goodbye, Cruel World!” This dates from the mid-fifties, and I’m not sure even then why someone thought the authorities would object. But this one was completely free to mail as is.

Okay, maybe he’s just squirting water between his hands. Sure he is. And the fact that he has found the Fountain of Youth “again”…it’s probably just me. This was a very popular gag, and seems to have been available with small boys of different races and colors.
Bathroom humor is a fairly common theme. Our era is proud of its openness about these things (a cartoon bear reminds us “We all have to go.”) But our ancestors were surrounded by horse-drawn vehicles, besides themselves having limited bathroom facilities and a medical community which considered bowel control to be essential for mental and physical health. So there are dozens of manure jokes and hundreds of outhouse jokes. They seem to have loved the lady with furs and lorgnette stopping by the road to step into an outhouse: just a sign that we all have to go, I suppose. This, for example, was a simple gag most anyone could appreciate without blushing.

But was the combination of kids and castor oil so commonplace that this slightly more explicit version would pass postal inspection?

Indoor toilets provided a world of naughty fun, too, particularly of the slightly snobbish variety. We could all chortle at the backwoods family who used the toilet seat as a picture frame and the bowl itself as a sort of kettle. Or there was the fellow from the country, washing his hair in this newfangled sink way too low to the ground. Bathtubs were not as common a source of fun, but they certainly made their postcard appearances. The most frequent use of the tub was the one holding half a dozen people at once, letting you know how crowded the hotel is or how friendly your neighbors are. None of this shocked me, nor did I suppose the postal inspectors were appalled. But I was stunned for a few moments by this image.

There were people who wanted the very phrase “Come up an’ see me some time” banned for public use. The use of a cigarette holder in the tub suggests sinful luxury. And, um…well, there were only two uses for a hot water bottle with a tube on it, and neither one could be discussed in mixed company.
But this is a postcard from the 1930s or thereabouts. Wait until you see a couple of these from the 1910s.