Calvin Knerr was born December 27, 1847 and grew up with a father who was a lay homeopath and an uncle who knew Hering at the Allentown Academy. He attended The Allentown College Institute and graduated from Hahnemann Medical College in 1869 (along with Cowperthwaite and T.L. Bradford).
He then entered the office of Dr. Constantine Hering as his assistant. The diary he kept while living in Hering's house became The Life of Hering, published in 1940.
From 1873-4 Dr. Knerr studied in Berlin, Vienna, and London. In 1874 he married Melitta Hering, one of Hering's daughters, and resumed his duties as Hering's assistant. In 1878 and 1879 he published 2 editions of his book, Sunstroke and Its Homeopathic Treatment.
Upon Hering's death in 1880 Knerr became responsible for the completion of the 10-volume Guiding Symptoms. Originally working with Dr. Charles Mohr and Dr. Charles Raue, and later working alone, Knerr completed Hering's masterpiece in 1895.
Dr. Knerr spent 5 years writing his 2-volume Repertory to the Guiding Symptoms, which was published in 1896. This repertory to Hering's materia medica never saw widespread use.
Knerr used the same structure throughout as found in the Guiding Symptoms, even to including the "relationships" at the end of the book and giving the remedies the four lines of grading. This makes for a book that is bulky without being that useful in everyday study.
As a reference repertory for comparative research it has its own place. Knerr's repertory mixes pathogenic and clinical data but it also contains rubrics that are found nowhere else. Now available on computer, the complexity and difficulty of Knerr's repertory have given way to ease of access through simple search functions.
For a considerable length of time Knerr's repertory remained out of print. After a prolonged correspondence Dr. Knerr agreed to grant Messrs. M. Bhattacharyya and Co. the exclusive right of publication. He revised the whole work, portions of which he wrote anew for this edition.
In the 1941 Homeopathic Herald memoriam Dr. W. A. Pearson writes,
"His home on Camac Street was filled with books, pictures and mementoes pertaining to homoeopathy. The original letters (1813-1836) written to Constantine Hering by Samuel Hahnemann were probably the most prized possession."
"Several of these letters have been published in Hospital Tidings during the past year and afford much reliable information concerning Homoeopathy. Most of these historic treasures have been presented to The Hahnemann Medical College."
His was a life of unceasing work, and even when confined to bed he actually prescribed for his patients. He died on September 30, 1940.
To quote Pearson again,
"Dr. Knerr lived a long and useful life and we should rejoice that he fulfilled a very important mission so ably."