Here is the article.
Dear Sir. About twelve years ago when I was Parochial Schoolmaster at Reay, in the course of my walking on the shore of Sandside Bay, being a fine warm day in summer, I was induced to extend my walk towards Sandside Head, when my attention was arrested by the appearance of a figure resembling an unclothed human female, sitting upon a rock extending into the sea, and apparently in the action of combing its hair, which flowed around its shoulders, and of a light brown color. The resemblance which the figure bore to its prototype in all its visible parts was so striking, that had not the rock on which it was sitting been dangerous for bathing, I would have been constrained to have regarded it as really an human form, and to an eye unaccustomed to the situation, it must have undoubtedly appeared as such. The head was covered with hair of the color above mentioned and shaded on the crown, the forehead round, the face plump. The cheeks ruddy, the eyes blue, the mouth and lips of a natural form, resembling those of a man; the teeth I could not discover, as the mouth was shut; the breasts and abdomen, the arms and fingers of the size in which the hands were employed, did not appear to be webbed, but as to this I am not positive. It remained on the rock three or four minutes after I observed it, and was exercised during that period in combing its hair, which was long and thick, and of which it appeared proud, and then dropped into the sea, which was level with the abdomen, from whence it did not reappear to me, I had a distinct view of its features, being at no great distance on an eminence above the rock on which it was sitting, and the sun brightly shining.
Immediately before its getting into its natural element it seemed to have observed me, as the eyes were directed towards the eminence on which I stood. It may be necessary to remark, that previous to the period I beheld the object, I had heard it frequently reported by several persons, and some of them person whose veracity I never heard disputed, that they had seen such a phenomenon as I have described, though then, like many others, I was not disposed to credit their testimony on this subject. I can say of a truth, that it was only by seeing the phenomenon, I was perfectly convinced of its existence.
If the above narrative can in any degree be subservient towards establishing the existence of a phenomenon hitherto almost incredible to naturalists, or to remove the skepticism of others, who are ready to dispute everything which they cannot fully comprehend, you are welcome to it from,
Your most obliged, and most humble servant,
Munro was not the first person to see a mermaid in that area. In 1804 two girls reported seeing mermaids there. Coincidence? Surely not!