"What a lovely thing a rose is!"

Excerpted from The Memoirs of Sherlock Holmes by Arthur Conan Doyle, ©1894:

“Thank you. I have no doubt I can get details from Forbes. The authorities are excellent at amassing facts, though they do not always use them to advantage. What a lovely thing a rose is!”

He walked past the couch to the open window, and held up the drooping stalk of a moss-rose, looking down at the dainty blend of crimson and green. It was a new phase of his character to me, for I had never before seen him show any keen interest in natural objects.

“There is nothing in which deduction is so necessary as in religion,” said he, leaning with his back against the shutters. “It can be built up as an exact science by the reasoner. Our highest assurance of the goodness of Providence seems to me to rest in the flowers. All other things, our powers our desires, our food, are all really necessary for our existence in the first instance. But this rose is an extra. Its smell and its colour are an embellishment of life, not a condition of it. It is only goodness which gives extras, and so I say again that we have much to hope from the flowers.”

Percy Phelps and his nurse looked at Holmes during this demonstration with surprise and a good deal of disappointment written upon their faces. He had fallen into a reverie, with the moss-rose between his fingers. It had lasted some minutes before the young lady broke in upon it.

“Do you see any prospect of solving this mystery, Mr. Holmes?” she asked, with a touch of asperity in her voice. 

This was an odd little aside that had nothing to do with the story.  My guess is that it's just something that was important to Mr. Doyle, so he sort of shoehorned it in.

All of Arthur Conan Doyle's books are in the public domain, and may be read online or downloaded freely from Project Gutenberg, HERE.