338 SELECTED ARTICLES. 
water of M. Nees d'Esenbeck, and the solid portion appears 
to be the oscillaria undergoing decomposition, and which can 
never be deprived of its earthy particles. 
Journ. tie Pharm. and Annalen de Pharmacie. 
ART. LVIII.— REDUCTION OF THE DEUTOXIDE OF MER- 
CURY IN OINTMENTS. 
M. Refueville, Jr. in a letter to the Editors of the Jour- 
nal de Pharmacie, states that in the preparation of the oint- 
ment of the deutoxide of mercury with a certain amount of 
the oxide to the ounce of lard perfumed with orris root and 
lavender, he has remarked that this mixture at the end of 
several months assumes a metallic aspect, deep in proportion 
to the amount of the oxide employed. 
M. Planche had made some investigations into this subject, 
and had observed that in the red precipitate ointment made 
with lard, the reduction took place in four months, while with 
the basilicon ointment it did not undergo this change until the 
end of six. M. Refueville directs attention to the fact that 
all the ointments thus altered in colour are rancid, and sug- 
gests the probability that the matters added to the oily sub- 
stance in the basilicon ointment preserve it from rancidity; 
upon which supposition the longer time occupied in working 
the change of deoxygenation in this unguent is explained. 
The basilicon of the French Codex contains wax, rosin, black 
pitch and oil. 
