122 CONIUM MACULATUM. 
efit. In this way its external use is sometimes 
serviceable. : 
In old syphilitic affections, it is occasionally 
useful. It has been recommended in hooping 
cough, but itis not a perfectly safe medicine for 
children, owing to the difliculty of ascertaining when 
its constitutional effects take place in them.—I 
am informed on the best medical authority, that it is 
of great use in some cases of hemicrania, which 
are not regularly intermittent. 
The most common form of preserving the 
Hemlock for use, as well as the most convenient for 
its exhibition, is that of the inspissated juice or ex- 
tract. It is well known however, that the extracts 
kept in our shops differ materially in their strength, 
so that in beginning from a new parcel, the physi- 
cian can seldom predict the degree of operation of 
his first doses. In some instances very great quan- 
tities have been taken without the least effect. 
The extract is apt to proye inert when the plant 
is gathered too young, when the evaporation is con- 
ducted with too much heat, when a decoction of 
the dried plant has been evaporated instead of the 
fresh leaves, and lastly when the extract itself has 
become old. To give the extract its due strength, 
the plant should be collected at full maturity, while 
in flower, or in fruit provided it remains green, and 
