40] 
to the list of hydrocyanic acid plants, which was communicated by 
me with explanatory details to the meeting of the British Associa- 
tion at York, in 1906. I hope to append this list, brought up to 
date and arranged according to natural orders, to my second report. 
Economically: the use in washing ap 
(¢.9., Quillaja), For further information I refer to the excellent 
substanzen,” 1904. Unfortunately in the case of saponins there 
are no well-defined chemical characteristics like those of hydro- 
cyanic acid, but for practical purposes three properties suffice : in 
the first place, the marked frothing of a plant extract containing 
saponins, which persists at very great dilutions (sometimes ‘e 
1 in 3,000, occasionally even to 1 in 15,000); secondly, 
hydrolysis of glucosidal saponins by boiling with dilute acids an 
the colour reactions of the sapogenin formed; thirdly, as ~ 
important indication of the general toxicity, the determination - 
the haemolytic power. In the following report, the figures 1-30 
mean, for instance, that an extract of the plant at a eo meanne 
of 1 part in 300 dissolves an equal volume of diluted (1 per cent.) 
fresh blood of the ox. 
; th 
* The medicinal notes have mostly been taken from ds crepe wa 
late Prof. G. Dragendorff: Die Heilplanzen der versciie 
hie, 1898. 
Zeiten ; ihr nwendung, wesentliche Bestandtheile one Geschichte, 10: 
' i k vol. I. was 
the world, and their distribution in natural orders. bei % sl a reels to 
published in 1893 at Batavia and vol. II. in 1900; vol. 12). 
the press in 1910, 
