168 THE NEW ZEALAND FAMILY HERB DOCTOR, 
concerned, but it has no direct antacid property; that is, it 
has no influence upon any acid it‘meets with in the alimentary 
canal. Dose, 5 to 10 grs. 3s. per oz. 
Locwoop. — The sliced heart-wood of Hematoxylon 
Campechianum, a native of Campeachy. Logwood is chiefly 
employed as an astringent in affections of the alimentary 
canal, as diarrhoea, chronic dysentery, and some forms of 
atonic dyspepsia. It is often given to children. Dose of 
decoction of logwood, 1 to 2 fl. ozs.; of extract, 10 to 80 grs. 
Safe. 
MANGANESE, (Oxide of, called also black oxide of man- 
ganese).—Is found native, sometimes crystallized, sometimes 
amorphous. As met with in commerce it is a black, heavy 
powder, devoid of odour and taste, and when heated to 
redness evolves oxygen. The black oxide is not used in 
medicine. 2d. per oz. | 
Manna.—A concrete saccharine exudation from the incised 
bark of Fraxinus Ornus, obtained by making incisions in the 
stems of the trees, which are cultivated for the purpose 
chiefly in Sicily and Calabria.—A very mild laxative, adapted 
for children, also a pleasant adjunct to some purgative 
draughts, though it sometimes causes flatulence and griping. 
Dose, 1 drachm to 1 oz. 6d. to 1s. per oz. 
Morpuia, Muriate of.—The hydrochlorate of an alkaloid 
prepared from opium. Morphia has both a soporific and a 
convulsant action. Clinical experience has shown that 
morphia possesses the anodyne and soporific powers of opium, 
and gives to the drug most of its valuable properties.. At the 
same time its action is as a rule more agreeable, having less 
tendency to cause headache, nausea, and constipation; it is 
also much less stimulant in its operation, and does not produce 
the full diaphoretic effects of opium. Since the sub-cutaneous 
method of administration has become general, the use of morphia 
to alleviate pain has been much extended. It is statedto cause 
less constitutional disturbance when given hypodermically than 
by the mouth. Moreover, in some rare cases it seems to give 
