60 ODOROGRAPHIA. 
separated the perfume of the most delicate flowers, and from cow’s 
milk were able to recognize the odours of the plants eaten by the 
animals. 
From some plants which contain the odorous principle in 
exceedingly minute quantity, this principle has been isolated by 
Chardin and Massignon by distillmg with a small quantity of 
water the pommades or oils saturated by the process of enfleurage, 
saturating the distillate with salt and agitating it with ether. On 
evaporating the ether, the essence remains. In this way they suc- 
ceeded in eliminating small quantities of the essence of strawberries, 
of raspberries, of tubereuse, jasmine, and pinks. These rarities 
were very troublesome and expensive to make, and on a large scale, 
would be attended with many difficulties, such as the danger of the 
explosion of the ether vapour. This difficulty, on a small scale, 
could be overcome by substituting chloroform, because chloroform 
and its vapour are not inflammable and it evaporates most com- 
pletely and rapidly, leaving no trace of unpleasant odour as ether 
does ; chloroform may be expensive, but it could be recovered by 
condensation of its vapour. As regards the first part of the 
process, it would certainly be necessary to employ as little heat as 
possible in the distillation of the grease, to avoid decomposition ~ 
both of the grease and of the odorous principle. This might be 
accomplished by using a vacuum-still, such as are made by Berjot 
of Caen and Brinjes and Goodwin of London. 
In 1879 a patent was taken out by Massignon * for the extrac- 
tion of perfumes by making use of the solvent power of methyl 
chloride. The economic production of this liquid on a large scale 
from the molasses left in the manufacture of beet-sugar was in- 
vented by Camille Vincent +, for which he was awarded a gold 
medal by the Société d’Encouragement. Methyl chloride in the 
gaseous state is dried, purified, and condensed by pressure into 
strong metallic reservoirs. In this state it is a colourless, very 
mobile fluid, having a sweet ethereal odour. It boils at about 
— 23°C. under the normal atmospheric pressure of 0°76 m. It 
has the property of dissolving fatty bodies, resins, and essential oils. 
The apparatus used for the extraction of perfumes by the aid of this 
liquid is described { as :—1, a digestor, in which the flowers are 
* Brevet 180967, May 30. + ‘La Nature,’ June 21, 1879, 
¢ ‘ Bulletin de Ja Société d’Encouragement,’ Dec. 1879. 
