The Microscope. 261 



altogether from the same preparation. If a section of any organ, 

 rich in various tissues, be laid in a mixture of several pigments, 

 each histological element is stained by that for which it possesses 

 the greatest attraction. If a certain part have for two or more 

 dyes an exactly similar attraction, it then takes up both or all, 

 and a mixed colour is the result. Examples of staining by 

 chemical processes are, among others, the various reactions on 

 amj^loid substance. "When Ourshmann employed methyl green 

 for staining amyloid-degenerated nerves, all the normal parts 

 were coloured green, the hyaline cylinder light blue, and the 

 amyloid substances violet. The latter, therefore, entered into 

 chemical union with the pigment, the new body only showing a 

 colour differing from that of the dye. Thus, too, the rose-orange 

 staining of red blood-corpuscles by rosin may be regarded as the 

 result of a chemical reaction. 



The author concludes by expressing the opinion that the 

 staining problem of the future will be solved by the aid of chem- 

 ical reaction. — Journal of Royal Society. 



REVIEWS, 



The Essentials of Histology. By E. A. Schafer, F. R. S., Profes- 

 sor of Physiology in University College, Londou. Octavo volume 

 of 246 pages. 281 illustrations. Cloth, $2.25. Lea Brothers & Co. 

 1885. 



The chief object of this excellent work is to give the student 

 of histology directions for the microscopical examination of tis- 

 sues. The illustrations are similar to those found in the second 

 volume of the ninth edition of Quain's Anatomy, the histology 

 of which was written by this same author. The work is divided 

 into forty-three lessons, each lesson supposed to occupy from 

 one to three hours. The author gives us only those methods of 

 work which have proved successful in his hands, and therefore 

 all the more valuable. It is a valuable acquisition to our micro- 

 scopical library and will become a work of daily reference. It 

 is brief, concise and clear in all its statements. It should be in 

 the hands of every worker in animal histology. 

 Methods of Research in Microscopical Anatomy and Embry- 



