2i2 THE AMERICAN MONTHLY [Sep 



plants. Thus was the seed sown, but it was nearly a cen- 

 tury before any further advance was made, until in the 

 year 1849 the botanists, Messrs. Groppert and Cohn, used 

 carmine solution to study the rotation of the cell contents 

 of Nitella flexilis ; five years later Hartig made exhaus- 

 tive experiments as to the possibility of fixing the car- 

 mine in relation to the capacity of the different elements 

 of the plant cell ; that is to say, of stopping the staining 

 process when, owing to their varying affinity for carmine, 

 the elements were each stained to a different degree, and 

 thus differentiated ; he was so far satisfied with his results 

 as to prophecy a great future for the new process. 



Already, the knowledge of these experiments had spread 

 widely, and two years later, A. D. 1856, we find Lord Syd- 

 ney Godolphin Osborne, who was deeply interested in 

 botany, growing plants in carmine solution, and in the 

 next year the chemist, Maschke, of Breslau, endeavoured 

 to further his botanical researches with the same stain. 

 So far all the recorded experiments had dealt only with 

 plant histology, and it was reserved for Grerlach, anato- 

 mist, of Erlangen, to first describe the results obtained 

 by the new method in the field of human morphology ; he 

 it was who urged on the histologists of his day the ne- 

 cessity of further experiment, both with this and with 

 other stains ; and, if to Prof. Reichert is due the credit of 

 planting the seed, to Gerlach is certainly due the credit of 

 so grafting the resulting shoot as to give it its present- 

 day character. 



In answer to his appeal there arose a school of histolo- 

 gists devoted to mastering the technique of staining, and 

 in 1871 Weigert succeeded in staining the Cocci-zooglcea, 

 as well as the nucleus of the cell, by means of an ammo- 

 niated solution of carmine followed by treatment with mu- 

 riatic acid-glycerin ; in the following year Messrs. Eberth 

 and Wagner succeeded in staining Cocci, but not Bacilli, 

 with Hematoxylin, and subsequently Weigert discovered 



