168 ODOROGRAPHIA. 
coniferin by means of fermentation, and treat one or other with 
oxidizing agents. For the first production I use the following 
method :—Ten parts of coniferin are dissolved in hot water and 
the concentrated solution is allowed to flow slowly into a gently 
heated mixture of ten parts of bichromate of potassium, fifteen 
parts of strong sulphuric acid, and eighty parts of water; the 
whole is heated for about three hours almost up to the boiling- 
point of the liquid. The vanillin produced in this way may be 
isolated either :—1. By shaking the solution, when it has been 
filtered and become cold, with ether, separating the etherate from 
the aqueous solution, evaporating the ether, and purifying the 
dark coloured residue by repeated crystallization. Or, 2. By 
combining with a boiler in which coniferin has been treated for 
about three hours with the oxidizing mixture, a distillatory 
apparatus, and then by distilling the contents till only one fifth 
of their original volume remains, and by treating the distillate in 
the before described manner with ether to obtain a pure product, 
and by treating the residue in the same way to obtain the last 
traces of an impure vanillin. The artificial vanillin can also be 
obtained from an aqueous extract of all those parts of conifera in 
which coniferin 1s present, the impure solutions being boiled for 
some time to separate the dissolved albumina, filtered, and 
strongly evaporated. 
“ For a quick, but sufficiently exact determination of both the 
coniferin and sugar which are contained in the concentrated 
solutions, | evaporate them perfectly in a water-bath, and the 
residue is dried at 100°C. On every ten parts of what remains in 
the concentrated solutions, fifteen parts of bichromate of potas- 
sium and twenty parts of concentrated sulphuric acid must be 
taken, and the quantity of water must be administered according 
to the concentration of the solution, The further process is as 
ahove. 
“The coniferin decomposes under the influence of ferments into 
sugar and a crystallized substance which, in contact with damp 
air, also changes slowly and incompletely into vanillin, To obtain 
vanillin from this substance quicker, I treat it with an oxidizing 
mixture of bichromate of potassium and sulphuric acid. The 
vanillin obtained and purified in either way is proved in all cases 
completely identical to the natural vanillin.” 
