"It is impossible as I stated it, and therefore I must in some respect have stated it wrong."Let's compare this to the famous Quintessential Quote #1 from The Sign of Four: "How often have I said to you that when you have eliminated the impossible, whatever remains, however improbable, must be the truth?"
-- Sherlock Holmes, "The Adventure of the Priory School"
The "eliminate the impossible" quote refers to the simple process of elimination, or "process of exclusion" as Holmes calls it in A Study in Scarlet. That is certainly a key element of any investigation, whether criminal or chemical. And the way it is stated usefully focuses on not excluding the improbable along with the impossible.
"It is impossible as I stated it," on the other hand, focuses on the seemingly impossible and warns us to look beyond the surface appearances. What appears to be impossible may not be.
If I were a consulting detective or his Boswell, I think I would find that a very useful warning indeed.
What's your favorite quote from the world of Sherlock Holmes?