156 
MISCELLANY. 
viously discovered*" lanthanium. This metal Professor Mosander has 
called didym (as being the twin-brother of lanthanium;) he has not 
yet discovered any good method of effecting its complete isolation. 
The oxide of didym imparts to the oxide of cerium its brown color, and 
also confers on certain salts of yttria, a more or less deep rose-red, or 
amethyst hue. Pure oxide of cerium and pure oxide of lanthanium are 
almost colorless. Hydrated oxide of ceiium has a sulphur yellow color. 
Sulphate of didym has a tint intermediate between rose-red and amethyst. 
When the brown oxide of didym is subjected to a strong red heat, it 
loses its color and assumes a dirty white appearance. Its density does 
not, however, seem changed. — London P harm. Trans., from Poggen- 
dorjf's Annalen, No. 7, 1842. 
On Coca and Matico. By Dr. Martius. — Dr. Martius examined a 
specimen of the noted Coca or Ypada of the Brazils. It is the leaf of 
the Erythroxylon Coca growing on the other side of the Andes. These 
leaves are chewed by the native Indians, as we use tobacco, a small 
pinch is wetted with saliva, and made into a ball with unslaked lime. 
The Indians who are capable of undergoing great fatigue, will, during 
the most strenuous exertion, subsist on one or two spoonfuls of maize 
flour mixed with water, daily, and their coca. The use of this plant 
has become as much an abuse amongst them, as opium-smoking in 
China, Its effect is to deaden sensation, and produce even madness; 
it has, morally, a most pernicious influence on those who take it in 
excess. 
The Matico, or Matica, so highly esteemed in Peru, Dr. Martius be- 
lieves to be a species of Phlomis. The tree grows in the interior of 
Peru, also on the other side of the Andes. Its leaves are said to possess 
marvellous medicinal properties. The preparation for use amongst the 
Indians is very simple, the leaf is dried and finely powdered, and the 
dust, sprinkled on wounds, is said to effect cicatrization very speedily. 
The Indians use an infusion of the fresh leaves as an aphrodisaic, and 
attribute to them the power of arresting arterial haemorrhage, even if a 
large vessel be wounded. 
Ibid, from Ganger's Repert., 1842. 
On Menyanthin. By Brandes. — The presence of coloring matter, 
sugar, and organic substances, soluble in alcohol, and the decomposition 
by heal, are the chief difficulties to contend with in the preparation of 
menyanthin. The following method will be found to be the most ad- 
