GLTCEEINE (TRI-HYDKIC ALCOHOL). 315 



2 lb., xanthogenate of soda 1 lb. The following mixtures are also 

 used as insecticides : — 



TABLE LXIII. — Showing Composition of Mixed Aitiyl Alcohol Insecticides. 



Lb. Lb. 



Green vitriol ....... 1 — 



Sulphate of alumina ..... — 4 



Amyl alcohol ....... 5 5 



Water (in gallons) 10 10 



An analogous insecticide is obtained thus : Dissolve 3 lb. of soft 

 soap in 10 gallons of hot water, and add after cooling with constant 

 stirring 6 lb. of ordinary alcohol, then 6 lb. of amyl alcohol ; before 

 making the mixture the insecticides are incorporated in the alcohol if 

 they are insoluble in water, and in the soapy solution if they are 

 soluble in the alkaline liquid. These preparations keep perfectly ; 

 when used they are diluted as circumstances may require. The 

 different applications of these insecticides are detailed under Soap. 



ii8. Glycerine, CH,OHCHOHCH,OH.— Preparation. — Gly- 

 cerine is present in all natural fats chemically combined with fatty 

 acids. It is a by-product of soap manufacture. 



Use. — Glycerine is only mixed with insecticides and anticrypto- 

 gamic solutions to increr.se their adherence to the leaves. It has been 

 recommended chiefly by Mohr. 



1 1 8a. Ordinary Ether, C,,Hj, . . C.,H.,.— Definition.— Ordinary 

 ether, erroneously termed sulphuric ether, is the oxide of ethyl. 



Preparation. — To 7 parts of ordinary alcohol there is added, 

 in the cold, 10 parts of concentrated sulphuric acid ; the mixture is 

 heated in a flask to 140° C. and 95 per cent alcohol is allowed to drop 

 therein so as to keep the temperature constant. In these conditions 

 alcohol is converted almost entirely into ether and water. 



2C,H,0H = c,H, . . an, + H,0. 



Properties. — Ordinary ether is a very mobile liquid, volatile, and 

 of a penetrating odour. It boils at 35-6° C. It dissolves in 10 parts of 

 water. [Highly explosive.] 



Action on Plants. — An atmosphere saturated with ether vapour 

 does not lower the germinative capacity of dry seeds, but it only 

 requires a small quantity, 3-7 cubic centimetres per 10 litres of air 

 (3-7 cubic inches per 10,000 cubic inches), to kill moist seeds. Ether 

 favours the assimilation of the plant in an analogous manner to 

 chloroform, but whilst it takes 0-5-0-7 of the latter to stimulate this 

 function, ether acts favourably in 5-6 per cent doses. This action 

 disappears w^hen the ether is low^er or higher than the figures indicated 

 (Latham), There is also a fixed dose to stimulate the respiratory 

 functions. 



Use. — Conchijlis ambignella, Hub. (cochylis of the vine) ; Eudemis 

 hotrana (eudemis or tortrix of the grape). — Audebert used with 

 success against the caterpillars of these two butterflies the following 

 liquid : Ordinary ether 10 lb., essence of absynth 1| lb., ammoniate 

 of copper 8^ lb., pare rosin 15 lb., carbonate of soda 15 lb., water 95 



