Roughly the first half of this work is on "war neuroses." The second half is on "infective and other disorders," including gas poisoning. Hurst greatly expanded the first section after experience as a neurologist in English war hospitals. In the preface to the first edition (1917) Hurst points out that he changed his name to Hurst from Hertz "because under present conditions it is natural for one of English birth and English descent for several generations to be unwilling to retain a German name." Digital facsimile from the 1918 edition from the Internet Archive at this link; of the 1917 edition from the Hathi Trust at this link.