for one thing-譬如，舉個例子的意思。全句我的理解為：

There was so much to read, for one thing, and so much fine health to be pulled down out of the young breath-giving air.  有太多東西要看了，譬如，就那些新鮮東西（證券之類的書籍，下一句提到）就讓我夠嗆。