Her first two letters from Switzerland had been very pleasant; but after that there had seemed to have crept over her a melancholy which she unconsciously transferred to her words, and which he could not but taste in them,--at first unconsciously, also, but soon with so plain a flavour that he recognised it, and made it a matter of mental inquiry. 
After those first two letters, however, there seemed to have crept into them an unconscious melancholy, which he soon recognised and thought much about. 