CHEMISTRY AND CRYSTALLOGKAPII V. 21/ 



spheres arranged in twa sets of tetraheclral order (one represent- 

 ing C and the other set H.J, and (2) the supposition that the 

 X ( :=Z) spheres are sHghtly larger than the hydrogen spheres. 

 The new assemblage can be divided into practically exact tetra- 

 hedral arrangements to represent gaseous CH^ {=^Z^H^ where 

 Z = 3), in which the distance between the centres of the 

 hydrogen spheres is exactly 5/3 of the sphere-diameters (all 

 assumed ecpial), and in other respects it seems to be very similar 

 to Pope's arrangement, though somewhat more closely packed. 



The case of benzene is somewhat similar. Pope's model 

 consists of alternate layers of 6-membered rings, each C.^H., and 

 alternately reversed. : the carbons in each layer are separated 

 by hydrogens, but each carbon is in contact, zigzag fashion, 

 with two carbons from the other layer. There is a central 

 hexagonal hollow (a tube in the aggregate). My scheme for 

 benzene consists of three layers, of which the middle one is a 

 hexagonal of Z spheres, and the other two are -ZgHg, one being 

 reversed with regard to the other. The structure has an 18- 

 sided hollow in the middle, which does not form a tube in the 

 aggregate. The relationships of the ortho-, meta- and para- 

 positions appear to be the same as in Pope's scheme. 



Insect Borne Disease. — The Rhodesia Scientific 

 Association's Gold ^^ledal for an original paper advancing the 

 knowledge of the transmission of any insect-borne or arachnid- 

 borne disease affecting Rhodesia, has been awarded to Dr. Edward 

 Hindle. A.R.C.S., F.L.S., Beit Memorial Research Fellow, Mag- 

 dalen College, Cambridge, for his paper on " The transmission of 

 Spirochccta Dnttoni." 



Ostrich Farming in Gfrmany.— The Journal of 

 the Royal Society of Arts (Vol. 60, p. 128) briefly describes the 

 development of the Hagenbeck ostrich farm at Stellingen, near 

 Hamburg. The farnx was founded three years ago and has in- 

 creased rapidly in size and importance. The proprietor's theory 

 that the ostrich would grow a heavier crop of feathers in colder 

 countries than in his native tropics has been experimentally 

 proved correct. The Stellingen farm holds two Cape female 

 birds, two each from Senegal and Somaliland. and eight from the 

 Blue Nile country, the last being considered the finest birds, and 

 belonging to a species that is becoming very rare. The proprietor 

 possesses a farm for similar purposes in German-West Africa, 

 and is establishing another near Trieste 



