Few men have applied themselves to the accurate notation of pathological appearances more thoroughly than Dr. Howden. He was amongst the first to investigate the lesions in the morbid brain, and for some forty years he has systematically studied the whole subject. His index cannot fail to be of the utmost value for the purposes of connotation and research. Everyone must have experienced the weariness of referring back to pathological records and case books for information as to special lesions and their relations to cases. This work affords a ready means of reference to recorded data regarding each particular disease or lesion. By its regular employment the pathologist of any institution can with the utmost ease analyse his records in a very short space of time. Say that he divides his autopsies into hundreds and notes the various lesions under the different heads, he can, on the completion of a series, almost at a glance note the frequency of each per cent., can relate one with another, and can refer to the individual career in which they have occurred. The list of lesions is very comprehensive. The only suggestion that can be offered is that in the next edition it would be well to interleave the book so as to allow of the introduction of notes on microscopic appearances. We have no hesitation in saying that the index should be kept regularly written up in the pathological department of every hospital and asylum, for with a minimum of work it gives a maximum of utility to the records of facts.