THE ODOUR OF ROSE. 63 
It may, however, be here recorded that the use of methyl] chloride 
as a solvent is recognized in the Colony of Victoria, and “‘ concrete 
oils” are there obtained by a simple process regardless of the 
disputes between French patentees. Mr. J. K. Blogg, manufac- 
turing chemist of Melbourne, gave evidence before the Royal 
Commission of Enquiry into the Vegetable Products of Victoria * 
to the following effect :—“ Concrete oils are by far the choicest 
and most valuable of all perfumes, and though the manufacture of 
them requires a little skill, yet the process is not beyond the reach 
of average Victorian intelligence. The plant required is not very 
expensive. A jacketed vacuum-pan (still) fitted with an air-pump 
and condenser, a close macerating vessel, and a receiver is all that 
is required. Fresh flowers, free from stalks, are put into the 
macerating-vessel, which is then filled up with deodorized methyl 
chloride. The flowers are allowed to remain in contact with this 
fluid for about 10 or 15 minutes. The solvent has during this 
time extracted the essence and holds it in solution. This solution 
is now transferred without exposure to the vacuum-pan, the pump 
is set in motion, quickly at first, and afterwards at a steady rate, 
to maintain a vacuum of half an atmosphere. The temperature in 
the vacuum-pan is at the same time raised to 98° F. The vacuum 
in front of the methyl chloride causes it to evaporate very quickly 
at a low temperature, the vapour passing from the pump into the 
condenser flows therefrom into the closed receiver, and is reserved 
for the treatment of fresh flowers. ‘The concrete oil will be found 
in the vacuum-pan, and may be collected after each distillation or 
left in the pan to accumulate with other subsequent operations. 
As the methyl chloride is very volatile, care should be taken to 
prevent its exposure in transferring from one vessel to another. 
“The methyl chloride may be deodorized by passing it, while in 
a gaseous state, through pure sulphuric acid. This might be done 
by evaporating from the vacuum-pan by means of the air-pump, 
the pipe from which might be made to pass to the bottom of a 
two-necked or Woulf’s bottle containing the acid, and thence on 
to the condenser from the other neck of the bottle. It would be 
necessary to keep the sulphuric acid warm in a sand-bath, so that 
the methyl chloride might not condense in the acid and fill up the 
bottle,” 
* No, 2, publ. by the Goy. Printer, Melbourne, p, 45, 
