Well thats true, a lot of older homes are well junk, they did some pretty crazy things. My uncle bought one that had what looked like 2x3's for roof joists!
What are the basement walls made out of in this place? Maybe you should jackhammer a section and dig down to the footing to see what you have.
The worst offenders I have seen are on cheaper homes built after WW1. A lot of them suck, can't beleive they have been standing for almost 100 years.