159 
of Edinburgh, Session 1866-67. 
firmed. In the space of one hour, a cubic inch of blood was frozen 
and liquefied four different times. The vessel in which it was first 
frozen was a thin drinking cup about two inches in diameter. 
For the sake of rapid effect, it had been kept some time previously 
in a freezing mixture ; and the blood, as soon as liquefied, was 
poured into a tube similarly cooled in the same mixture, to be 
again frozen, — and so on in succession. 
These results, I need hardly remark, are little more than a con- 
firmation of those obtained by Hewson nearly a century ago.* 
3. Note on a former Paper on the Theory of Double Refrac- 
tion. By A. R Catton, M.A., Fellow of St John’s College, 
Cambridge. 
4. A Preliminary Notice of the Akazga Ordeal of West 
Africa, and of its Active Principle. By Thomas R Fraser, 
M.D. 
This ordeal poison is referred to in the works of Du Chailluf 
and Winwood Reade ;J and several of its toxic properties have 
been described by MM. Pecholier et Saintpierre.§ A few speci- 
mens were sent to this country in 1861 by the Rev. A. Bushnell of 
Baraka, and these were very kindly given to the author by Mr 
Thomson of Glasgow ; and a further supply came from the same 
quarter in 1865. These gentlemen, and Dr Nassau of Bonita, 
supplied valuable and interesting information regarding its employ- 
ment. 
The poison is known in Africa as Akazga, Boundou (or M’Boun- 
dou), Ikaja, and Quai ; Akazga being probably derived from nkazga , 
which signifies pain or hurt. It is used as an ordeal for the detec- 
tion of real and superstitious crimes on the West Coast of Africa, 
in a large district which extends north and south of the equator, 
and many miles inland, and also in the adjacent island of Corisco. 
* The Works of William Hewson, F.R.S. Edited by George Sullivan, 
F.R.S., p. 17. 
f Explorations and Adventures in Equatorial Africa, 1861. 
J Savage Africa, 1862. 
§ Comptes Rendus, 1866, p. 809. 
