This is the sixth (and completing) section of the fourth volume of Kopaczewski's 2,500 page work on the biocolloids. Such a treatise promises small reward to any publisher courageous enough to undertake it, wherefore thanks to France. In essence, this work is (as it must be) a "review." As such it recommends itself to any beginning worker too lazy to familiarize himself directly with first publications. But Kopaczewski's treatise brings a second good feature: it is critical. Half of this fascicle (pp. 847-924) is devoted to author, subject, figure and table indexes (the last two interesting because unusual), the remaining half (pp. 763-845) to a discussion of narcosis. The first pages of the second half discuss history—the discovery of the narcotics, their widely differing chemical (they may be organic or inorganic) and physical character (faradization and cold), and the universality of the narcotic response (all cells may be thus poisoned).