82 THE PROIJLEM OF HORSE SICKNESS. 



safely say that most likely it cannot be solved in this way alone, 

 simply beceause the immunity obtained is not a reliable one. 

 Immunisation, therefore, is only a temporary remedy, but it 

 will have its practical usefulness as long as the disease is pre- 

 valent in South Africa. On the other hand, it has also its 

 drawbacks. The immunity of the salted horse lulls the pro- 

 prietor into a false security, and he takes risks which he other- 

 wise would noc take, frequently with the result that the immunity 

 breaks down. 



Conclusion. 



The solution of the problem of horse-sickness for the time 

 being lies in the protection of animals against infection. The 

 selection of the methods to obtain this end depends entirely 

 upon the number of animals to be protected, upon the conditions 

 under which they are held and exposed to infection. Thar 

 horse-sickness can be prevented should be clear, but success 

 entirely depends upon the energy of the individual who applies 

 the methods. 



The final solution of the problem is the eradication of the 

 disease from South Africa. That even this is feasible, and 

 will one day be possible, should be the conclusion that can be 

 drawn from this paper. 



MeSEMBRIANTHEMUM TortUOSUM.— Under the head- 

 ing " Channa, a delicacy of the Hottentots," the Journal of the 

 Chemical Society^' quotes some results of work done by Hartwich 

 and Zwicky on Meseiiibriaiithemiiin torttiosiini L. and M. expan- 

 siiiii I.., the former of which is commonly known as Hottentots 

 koinvgoed, the name Gaiiiia being applied not to that genus at all, 

 but to Salsola aphylla. The active constituent was found to be 

 the alkaloid mesemlirine. ChiHtciO^N. of which the leaves contain 

 .3 per cent, and the stems and roots .86 per cent. The alkaloid 

 dissolves freely in chloroform, alcohol, or acetone, sparingly in 

 ether, water or alkalies, and very sparingly in light petroleum or 

 benzene, ^^^ith vanadic sul])huric acid it gives a brownish-red 

 solution, a green tint developing on warming, and becoming 

 bright green after 24 hours. Mesembrine is unsaturated, acts as 

 a phenol, and has an action somewhat resembling, but distinct 

 from that of cocaine. Every branch of the mesembrianthemum 

 family includes species which do and which do not contain this 

 alkaloid. A wax containing 25 per cent, of saponifiable material 

 was found in the epidermis of the leaves. The unsaponifiable 

 part is a mixture of mesembrene CagH^,;, and mesembrol, 

 CsiH^.^O, or CgoHesO. 



* (1915) 108, Abstr. [1], 710. 



