Opening Passages: From A Study in Scarlet:
In the year 1878 I took my degree of Doctor of Medicine of the University of London, and proceeded to Netley to go through the course prescribed for surgeons in the army. Having completed my studies there, I was duly attached to the Fifth Northumberland Fusiliers as Assistant Surgeon. The regiment was stationed in India at the time, and before I could join it, the second Afghan war had broken out. On landing at Bombay, I learned that my corps had advanced through the passes, and was already deep in the enemy’s country. I followed, however, with many other officers who were in the same situation as myself, and succeeded in reaching Candahar in safety, where I found my regiment, and at once entered upon my new duties.
From The Sign of the Four:
Sherlock Holmes took his bottle from the corner of the mantel-piece and his hypodermic syringe from its neat morocco case. With his long, white, nervous fingers he adjusted the delicate needle, and rolled back his left shirt-cuff. For some little time his eyes rested thoughtfully upon the sinewy forearm and wrist all dotted and scarred with innumerable puncture-marks. Finally he thrust the sharp point home, pressed down the tiny piston, and sank back into the velvet-lined arm-chair with a long sigh of satisfaction.
Summary: Both A Study in Scarlet and The Sign of the Four have the same generic structure, only adjusted to take into the account that the latter is a sequel presupposing the former in several key ways. Both are framed by the Baker Street flat and Watson's incredulity; in both Watson's coming along as an observer is a relatively new thing. Both have a detour into dangerous locales with strange customs, Utah in the former and India in the latter, although the locale in each case is really literary locale, a set of tropes from sensational fiction, more than a geographical one. (One of the things that this does in both cases is that it lets Doyle embed an exotic travel-adventure story in his detective fiction, which is narratively useful not only for variety but also because it means he doesn't have to work very hard to explain why Holmes in particular is necessary to the case -- it's just completely different from ordinary crime in the big city, so it's not anything the local police could have seen before.) In both it is a significant part of the investigation to find someone in the big city. The Sign of the Four gives us a more polished version of the structure, although it also doesn't labor under the burden of having to start the whole thing off.
I think the reputation of A Study in Scarlet suffers in part because it's difficult for most modern readers to think of Mormons in Utah as exotic. But pretty much everyone (who wasn't themselves Mormon) thought of them as such at the time. It wasn't just the polygamy; we forget the active hostilities that broke out occasionally between Mormons and non-Mormons, or the times when portions of the Latter-Day Saint community were involved in a sort of low-key guerilla war with federal agents. To be sure, the Mormons were never as crazily sensationalized as rumor made them, but they took some getting used to, and had to make a number of compromises over the years to make it possible for people to get used to them. In any case, I don't really have a problem with this; I think one of the charms of reading nineteenth-century European literature about America is the chance to see the United States as a dangerous, exotic, foreign realm. Even though The Sign of the Four is a better story in almost every way, A Study in Scarlet stands up well.
In reading The Sign of the Four, I was particularly struck this time around with how the sheer quantity of Romanticism in it. This is particularly ironic given Holmes's complaint about A Study in Scarlet at the beginning:
He shook his head sadly. "I glanced over it," said he. "Honestly, I cannot congratulate you upon it. Detection is, or ought to be, an exact science, and should be treated in the same cold and unemotional manner. You have attempted to tinge it with romanticism, which produces much the same effect as if you worked a love-story or an elopement into the fifth proposition of Euclid."
"But the romance was there," I remonstrated. "I could not tamper with the facts."
"Some facts should be suppressed, or at least a just sense of proportion should be observed in treating them. The only point in the case which deserved mention was the curious analytical reasoning from effects to causes by which I succeeded in unraveling it."
Almost everybody takes Holmes at his word here, and his self-presentation as a purely rational creature as accurate. But after having made this complaint about there being too much romanticism in the previous work, he quotes Goethe twice, refers to Jean Paul, has a mini-discourse on sublimity in the middle of all of his analysis and investigation. He keeps bringing it in himself.
The mini-discourse on sublimity is particularly interesting, and worth quoting in full:
"Ah, well, there is no great mystery in that. But you will know all about it soon enough. How sweet the morning air is! See how that one little cloud floats like a pink feather from some gigantic flamingo. Now the red rim of the sun pushes itself over the London cloud-bank. It shines on a good many folk, but on none, I dare bet, who are on a stranger errand than you and I. How small we feel with our petty ambitions and strivings in the presence of the great elemental forces of nature! Are you well up in your Jean Paul?"
"Fairly so. I worked back to him through Carlyle."
"That was like following the brook to the parent lake. He makes one curious but profound remark. It is that the chief proof of man’s real greatness lies in his perception of his own smallness. It argues, you see, a power of comparison and of appreciation which is in itself a proof of nobility. There is much food for thought in Richter. You have not a pistol, have you?"
So here we have more Romanticism brought into the discussion by Holmes himself, in the aesthetic appreciation of nature, which leads him to touch on a point associated with sublimity -- our smallness in comparison to the vastness of nature. This naturally leads him to bring up Jean Paul, with whom he is obviously familiar (despite Watson's claim in A Study in Scarlet that he knew almost nothing about literature). Johann Paul Friedrich Richter, better known by his pen name, Jean Paul, is not much read today in English, but he was a noted comic writer who was also a significant contributor to the theory of the sublime, and was an influence on a number of people at the time, including Carlyle. Holmes gives a simple but entirely accurate summary of post-Kantian theory of the sublime by way of his allusion to Jean Paul. The essential idea is that in the experience of the sublime, we have the paradox that we recognize our sensible insignificance in comparison with some great thing suggestive of the infinite, but are exalted rather than humiliated by it because our ability to recognize the disparity between the two shows the significance of reason.
Jean Paul's own major contribution to the theory of the sublime was his argument that the humorous, which he also calls the romantically comic, is the inverted sublime; roughly, in the sublime we recognize our infinitude through our finitude, whereas in the comic we recognize our finitude through our infinitude. In the sublime we focus on the positive relation between the two, recognizing through insignificance of the senses the greatness of reason, whereas in the comic we focus on the disparity, recognizing through the greatness of reason the insignificance of our sensible selves. The sublime exalts, the comic annihilates, on the same ground. The fact that in the story the discussion of this is sandwiched between Holmes's poetic remarks on the sublimity of the world and one of the most comic episodes in the Holmes corpus, Toby's mistake, cannot possibly be accidental, and it's built up so carefully that the irony of this occurring given that Holmes has disparaged Watson's introduction of romanticism, cannot be accidental, either.
There are few possibilities here:
(1) Holmes himself is something of a Romantic to begin with, despite his objection. He is well read on Romantic authors like Goethe and Jean Paul, and he himself has a romantic aesthetic sense.
(2) Holmes is teasing Watson, by deliberately bringing romanticism into the story whenever he can. This fits with the fact that some of Holmes's comments seem to be hinting at various elements in the solution to the problem, a solution he has already figured out but that Watson has not. This possibility requires that (1) also be true, because Holmes can't do this unless he in fact knows Romantic literature quite well.
(3) Watson is teasing Holmes. Watson makes clear that he was very annoyed by the egotism of Holmes's objection, so one way to read all this is that he is getting back at Holmes by increasing or at least explicitly highlighting the amount of romanticism in the story, with Holmes himself depicted as a major culprit. This perhaps also fits with the fact that, despite Holmes's complaint about working a love-story into Euclid, the entire structure of The Sign of the Four (and part of what makes it more relatable than the first book, I think) is a love-story, the elements of which Watson depicts at considerable (even if understandable) length. It would be very easy to see this as a second prong of Watson's revenge in writing this book that is filled to the brim with romanticism.
Of the possibilities, (3) seems to be the one that fits the textual facts best, although it is perhaps less in the spirit of the Great Game; that is to say, I suspect that Conan Doyle himself is deliberately building the ironic contrast as an essential part of the story.
[ADDED LATER: I forgot to say something about the radio adaptations I listened to for both A Study in Scarlet and The Sign of the Four, from CBS Radio Mystery Theater. Both can be found online at Internet Archive. Both are competent, and reasonably faithful. I thought the narrative work for "The Sign of the Four" was especially good; they both, and especially "A Study in Scarlet" have the problem a lot of Holmes radio adaptations have, namely, that Watson sometimes slips out of sounding like the bluff British military man type into sounding like the nearly falling down into the grave from decrepit old age type, despite the fact that, at most, he can't be more than very early thirties in these stories. ]
Favorite Passages: From A Study in Scarlet:
"But the Solar System!" I protested.
"What the deuce is it to me?" he interrupted impatiently; "you say that we go round the sun. If we went round the moon it would not make a pennyworth of difference to me or to my work."
From The Sign of the Four:
Our course now ran down Nine Elms until we came to Broderick and Nelson’s large timber-yard, just past the White Eagle tavern. Here the dog, frantic with excitement, turned down through the side-gate into the enclosure, where the sawyers were already at work. On the dog raced through sawdust and shavings, down an alley, round a passage, between two wood-piles, and finally, with a triumphant yelp, sprang upon a large barrel which still stood upon the hand-trolley on which it had been brought. With lolling tongue and blinking eyes, Toby stood upon the cask, looking from one to the other of us for some sign of appreciation. The staves of the barrel and the wheels of the trolley were smeared with a dark liquid, and the whole air was heavy with the smell of creasote.
Sherlock Holmes and I looked blankly at each other, and then burst simultaneously into an uncontrollable fit of laughter.
Recommendation: A Study in Scarlet is Recommended, and The Sign of the Four is Highly Recommended. The latter is indeed one of the best works of detective fiction of all time, a fact which I think is sometimes hidden by its sitting in the shadow of the exceptionally memorable The Hound of the Baskervilles.