MILLER: THE PROPAGATION OF MEDICINAL PLANTS 115 
been taken up in conjunction with other problems, and have only 
been developed as progress might demand. The work has been done 
for the purpose of determining the practicability of growing certain 
drug plants upon a commercial scale, and the possibility of im- 
proving them through an application of the methods of plant 
breeding. All seed tests have been of a practical nature, and but 
little of the great mass of material upon the effects of various 
reagents and influences upon germination has been used. This 
material so far seems to have resulted in no new general laws 
applicable to commercial growers. Experiments upon the effects 
of light and darkness (Heinricher, 9) upon seed germination, tem- 
perature (Reynolds, 18) in relation to germination, treatment with 
warm water (Jensen, 12), sterilization of soil (Stone & Smith, 21), 
copper sulphate treatment (Bréal & Giustiniani, 2), electrical 
effects (Monahan, 16), soaking in chlorine water (Spatschil, 20), 
soil temperature (Brown, 3), action of ether and chloroform 
(Becquerel, 1) and delayed germination (Crocker, 5), have resulted 
in many data but few generalizations. Specific gravity tests, 
sterilized soils and the sulphuric acid treatment (Love & Leighty, 
14), have been used successfully and might be recommended for 
practical purposes. The forms under consideration and the results 
so far obtained are as follows: 
DIGITALIS 
More or less uncertainty exists as to the exact botanical source 
of this drug. The comparative medicinal value of the leaves 
from wild and cultivated forms, and the disputed methods of 
collection, curing and packing are unsettled questions of consider- 
able importance. The comparative value of the many species and 
horticultural varieties, their ease of culture, relative yield of 
crude drug, their flowering periods, hardiness and duration of 
growth are additional problems which must be investigated before 
the genus can be made to yield its best to the manufacture of 
medicine, 
Open field sowing was tried several times during two successive 
years. These tests were carried out both under practical field 
conditions and in ideally prepared seed beds. The results were 
complete failures and open seed sowing under field conditions 
