174 
PASSAGES FROM POPULAR LECTURES. 
is attached a heavy iron weight, so shaped that it can be fired 
from the mortar. The apparatus is worked as follows :—On 
a ship going aground near the shore, the weight is fired from 
the shore as near to the ship as possible; the weight sinks, 
and acts as an anchor for the hose, through which oil is 
pumped from the shore. The oil rises near the ship, and 
being blown towards the shore (in most cases vessels are 
wrecked on a lee shore) forms a track of fairly smooth water 
for the boats to traverse. In cases when the whole volume 
of water rushes along and breaks, the oil has little or no 
effect, and, consequently, this apparatus would then be use¬ 
less ; but in ordinary broken water, the appliance will, no 
doubt, be of considerable service. 
(To be continued.) 
PASSAGES FROM POPULAR LECTURES. 
BY F. T. MOTT, F.R.G.S. 
VI.—THE UMBELLIFER2E. 
FROM A LECTURE DELIVERED IN 1876. 
The ancient Greeks and Romans reckoned among their 
deadliest weapons the juices of three poisonous plants — 
aconite, hemlock, and poppy. Of these three the one whose 
name has come down to us with most historical prestige is 
hemlock. The world will never cease to remember with 
shame and grief the death of Socrates, nor that it was by a 
cup of hemlock juice that that noble life was lost. 
This famous hemlock may be taken as a type of an 
umbelliferous plant, that natural order which is popularly 
marked by its flowers being produced in umbels. There are 
plants not of this order which also bear their flowers in umbels, 
as the ivy, the onion, and the polyanthus. These are not 
numerous, however, and their umbels are nearly always 
simple. The true umbellate inflorescence, especially the 
compound form, is in general a good distinctive character of 
the order. 
Of these umbelliferous plants there are 1,500 species 
known to exist, which are classified into 150 genera,* showing 
an average of ten species to a genus, a very usual average 
* 1,300 species, 152 genera, according to Bentham and Hooker, 
Genera Plantarum.— [Ed.] 
