The few Sherlock Holmes stories I’ve read in that volume were fine with regards to language and theme; they are MUCH different than the movie, but I admit I’ve not read them all. The one exception I’m sure of is that it that he uses cocaine. We discussed the fact that at the time, cocaine was in all sorts of products and people thought it helped them think more clearly; it wasn’t recognized as a contraband, dangerous drug. My son is quite clear that this is bad and dangerous, and not something to be considered in this day and age, and he’s also expressed that he feels the drug doesn’t have a positive effect on Holmes – his view is in line with Watson’s, which you can read about below. I suppose you will want to consider this and decide how you want to handle it, and decide whether you think this book is appropriate for your son. Here is what Wikipedia says about Holmes’ drug habit – it does sound just awful spelled out like this:
“Holmes occasionally uses addictive drugs, especially when lacking stimulating cases. He believes the use of cocaine stimulates his brain when it is not in use. He is a habitual user of cocaine, which he injects in a seven-per-cent solution using a special syringe that he keeps in a leather case. Holmes is also an occasional user of morphine but expressed strong disapproval on visiting an opium den. These drugs were legal in late 19th-century England. Both Watson and Holmes are serial tobacco users, including cigarettes, cigars, and pipes. Holmes is expert at identifying tobacco-ash residues, having penned a monograph on the subject.
Dr. Watson strongly disapproves of his friend’s cocaine habit, describing it as the detective’s “only vice” and expressing concern over its possible effect on Holmes’s mental health and superior intellect.[21][22] In later stories, Watson claims to have “weaned” Holmes off drugs. Even so, according to his doctor friend, Holmes remains an addict whose habit is “not dead, but merely sleeping”.[23]”