320 On the Use of the Globe 



It has been my object to draw the attention of other chemists 

 to a method of studying Crystallography which I myself have 

 found profitable. It is true that I had never seen a globe 

 used in the study of Crystallography, nor had I met with 

 any suggestion of its applicability. I looked through all 

 the available crystallographic literature without finding any 

 indication of it. When the projection on the sphere is men- 

 tioned, it is always with a view to dealing with it according 

 to Miller's method by spherical trigonometry. 



In May 1893 I gave a demonstration to the Philosophical 

 Society of Cambridge (in connection with globes generally) 

 of the suitableness of black globes for studying crystals. 

 When I began to prepare this paper I made a further 

 thorough search through the literature, because I could not 

 believe that the person who first had the idea to project the 

 crystal on the sphere had done so with any other view than to 

 study it when he had got it there. I could not meet with a 

 copy of either Neumann's Beitrdge zur Krystallonomie, or 

 Grassmann's work Zur Krystallonomie und geometrischen 

 Combinationslehre, which are alluded to in the beginning of 

 Miller's Treatise on Crystallography, and I suspected that 

 one or both of these authors might have recommended the 

 use of the globe itself. A few days ago, through Messrs 

 Mayer and Miiller of Berlin, I procured a copy of Grassmann's 

 book. Its full title is Zur physischen Krystallonomie und 

 geometrischen Combinationslehre. Von Justus Giinther Grass- 

 mann, Professor am Gymnasium zu Stettin: Stettin, 1829. 

 It is the first number of the first volume of a comprehensive 

 work entitled Znr Mathematik und Naturkunde, which the 

 author proposed to complete by degrees. Nothing further 

 was, however, published ; but the single number is a sufficiently 

 remarkable work. It is worthy of note that he was obliged 

 to publish it at his own expense, as it found no acceptance 

 at the hands of the Scientific Societies or the Journals of the 

 day. This is no doubt the cause why it produced so little 

 effect in its time and is so difficult of access now. 



Of Neumann's Beitrdge also only the first fascicule ap- 

 peared, and I have not yet been able to see a copy of it. I am 



