I reported two cases of dislocation of the neck in the Boston Medical and Surgical Journal, April 25, 1907. Since that date three additional cases have been seen— one a slight subluxation that was self-reduced during the relaxation of sleep; the other two the cases reported below.
Besides these cases may be mentioned one seen1 in 1903. This makes a total of six cases in the past five years, five of them during the last two years.
These cases occurred in the practice of four different physicians. This experience tends to establish the probability that the condition is not a rare one, and that its apparent rarity may be due to lack of recognition.
It appears to be true with respect to some diseases that as they have become well understood they have apparently increased in frequency. Appendicitis may be mentioned as an example. Another instance is the disease