One of the best keynote books in Homeopathy—*yet rarely mentioned*—is:

📘 *Key-notes to the Materia Medica by Henry N. Guernsey, M.D.*

A brilliant gem that often goes unnoticed.

And honestly—*we must stop glorifying only one book of its kind.*

Every classical homeopathic text is an ocean of wisdom.

The issue is not the books — it’s our approach to studying them.

Here is an example:

In 1868, Dr. Henry N. Guernsey, MD, of Philadelphia (and a wonderful homeopath) published the following case that a colleague had communicated to him as an example of keynote prescribing...

"I am permitted to refer to the following case, extracted from one of the numerous letters sent me on this subject. In a case of typhoid fever, the last and worst of a malignant epidemic, where the disease had resisted the action of all the medicines given, and the attending and consulting physicians despaired of saving the boy,—a previously healthy, robust lad of sixteen years,—he was restored to his former rugged condition through the action of a remedy suggested solely by a “keynote” symptom.

My friend writes:

'As I went to his bedside one evening, I noticed a peculiar convulsive movement of the head, such as I had not before noticed in this or any other case, viz., the head jerked itself clear of the pillow, and then fell immediately back; this being constantly repeated. I at once recalled your keynote, for Stramonium. I went to my office, and on comparing the symptoms of the case with the symptomatology of that remedy, I was struck with the wonderful correspondence.

I then gave repeated doses of the 3d dilution, acting on my colleague's advice, but in twenty-four hours saw no improvement. The 30th was then given with no favourable result. I then gave a single dose of Stramonium 200 at night, and was delighted to see a smile on the face of the anxious mother when I called next morning. ‘Henry became quiet,’ she said, ‘very soon after taking the medicine, and has, for the first time, slept quietly.’

His convalescence was steady from this period. I gave no other medicine for ten or twelve days. Stramonium saved him, and your ‘key-note’ given me in the class was my only guide to it.'"