Here's something very amusing. In 1830 Isaac Leeser translated from German a book of instruction for Jewish children, and he called it Instruction in the Mosaic Religion. Translated From the German of J. Johlson, Teacher of an Israelitish School at Frankford on the Maine (link). The book is in the form of questions and answers and covers the gamut from matters of faith, tradition, and Orach Chaim-type practical law. Compared to the original it's actually quite pale, or, to put it another way, one imagines that the German author perceived a much higher level of learning than Leeser did among his potential audience in the United States. In any case, in a footnote in the section on Tradition, we find the following:
I was excited, as I was pretty sure this gematriya must be referring to something which no less than the author of the Hafla'ah, Rabbi Pinchas Hurwitz, ("The Rev. Chief Rabbi Mr. Hurwitz") had told Johlson (b. 1771), or which Johlson had heard from him indirectly.
However, whenever possible one should always try to look at the original, and when I did, I realized that Johlson was quoting his son, R. Hirsch Horwiz (original spelling). Probably, anyway. Oh well.
However, it gets even more interesting because while Johlson does quote R. Hirsch Hurwitz in another place, he does NOT give this gematriya here. Or anywhere in the book. And it isn't like I didn't look at various editions. I looked at the 1819, 1824, 1829 and even 1839 edition. Nothing. Now barring the possibility that I somehow overlooked it - and I looked through the entire book four times over - it seems that Isaac Leeser may have added this in by himself and amazingly ascribed it to the author, Johlson, for his very next note is one signed by himself (L.) in which he explains what a gematriya is. Very curious is all I can say. If you can find it in one of the original books, please do so and let me know.
Here is the one place, as far as I can tell, where Johlson did quote Hurwitz (and in other place, indirectly):
To make matters easier, here is how Leeser translated this footnote:
Finally, for posterity, here is a fascinating footnote by Leeser. The context is, Johlson had asked what is the duty of rabbis? His mildly reformist reply is that they must distinguish between true religion and the accretion of superstition and foolish customs that have been added to the law. In the translation, this continues, and then on the next page Johlson says that the rabbis can abolish customs that assumed the force or law under the principle of Et La'asot - and Leeser gives a lengthy footnote in which he claims to "explain" (rather than contradict) Johlson, about the importance of maintaining Hebrew as a language of the synagogue. Remember, this is 1830: