41] 
Seem.), and in H. scandens, Hiern; according to further investiga- 
tions of Boorsma (1902) this saponin is but slightly toxic. The 
leaf of H. rigidum, Seem., is used i.a. as a diuretic, Saponin is 
known in various other Araliaceae (Aralia, Panax, Polyscias, 
Trevesia). 
Hydrangea (Saxifragaceae). 
In Hydrangea there is a clear example of “transitory hydro- 
cyanic acid,” such as I have also demonstrated in ferns. In 1908 
and 1909 I sometimes found considerable quantities of hydrocyanic 
acid in the well-known ornamental plant, Hl. Hortensia, Sieb., and 
sometimes I did not. Probably the cyanogenetic principle dis- 
appears from the leaves in autumn; in any case the young leaves 
contain much more HCN than the older ones. In adult leaves of 
Hydrocyanic acid had not yet been found in this genus; in the 
bark of H. arborescens, L., saponin was discovered in 1887. 
Isopyrum (Ranunculaceae). oe 
A small quantity of seed obtained from a plant of /. pena 
L., grown at Kew was found to contain a little hydrocyanic acid. 
The investigation should be continued. 
Isopyrum is related to cyanogenetic genera. 
Jamesia (Saxifragaceae). i aes a 
The leaves and stems of J. americana, Lorr. et f 
appreciable amount of hydrocyanic acid. The liberation me sari 
in the leaf, bruised with water, only took place very slowly ; 
probably the leaf contains but little peabihe 
No details are known concerning the application 
—the only one of the genus—a shrub of the Rocky 
s of this species 
Mountains. 
b tter taste 
i iaey priser In Kew a second stone egy eee 
ee mesg OO a ae hydrooyanic acid, and 
is thi ies a ‘ 
ita om. 7 prageg #9 This paper sag cg 
Peel: prontios one Ag | Somsegnion, “ Semina 
Plant. I, 614, it is stated explicitly in the 
K, oblongae, amarissima.” 
