B.—CHEMISTRY. 67 
under regulations similar to those for industrial methylated spirit, and is 
largely used in the manufacture of formaldehyde, of methyl derivatives 
among dyestufis and fine chemicals, and for the purpose of crystallisation. 
The specially denatured alcohol, also free from duty, is allowed to 
manufacturers under restrictions compatible withthe safety of the Revenue, 
a very wide choice of denaturants being permitted. When, as frequently 
happens, a suitable denaturant is found in some intermediate product, or 
acid used, or produced during the manufacturing operations, or when the 
alcohol is a constituent of some mixed solvent, permission is the more 
readily granted for its use. An example of progressive policy in the use 
of pure spirit is the recent decision of the Board of Customs and Excise to 
allow the use of pure ethyl alcohol denatured with 2 per cent. of pure 
methyl alcohol in the production of insulin, without onerous Excise 
restrictions. It is understood that the recent action of the Board of 
Customs and Excise has been received with satisfaction by the Association 
of British Chemical Manufacturers. The quantity of pure and specially 
denatured alcohol used during last year was about half a million gallons. 
In the case of duty-paid spirits used for medical purposes, such as 
the preparation of tinctures, &c., and for scientific purposes in chemical 
laboratories, a rebate is allowed under the Finance Act of 1920, amounting 
to about 80 per cent. of the duty. 
While the responsibility rests on the Board of Customs and Excise of 
safeguarding the illicit use of alcohol, chemists have been represented on 
such commissions as that of the Industrial Alcohol Committee of 1905, 
whose recommendations led to the Revenue Act of 1906, in which the 
proportion of wood naphtha was reduced to 5 per cent., permission being 
also given for the payment of an allowance of 5d. per proof gallon or about 
‘8d. per bulk gallon on British spirits used for industrial purposes, in 
consideration of the increased cost of the spirits owing to Excise 
restrictions. 
Be) An important alcoholic liquid that has been liable to imposts from the 
time of Charles IT. is beer, and it was charged according to its strength or 
weakness as judged by the palate. After the application of science to brew- 
ing about the middle of the eighteenth century, the saccharometer was 
introduced, the pattern due to Bate being still in use for Revenue purposes, 
Tn 1850 an investigation made by the then Government Chemist, Mr. 
Phillips, and his assistant, Mr. Dobson, established a quantitative relation- 
ship between the proportion of alcohol produced in the process of fermenta- 
tion and the solid matter previously in solution in the worts that had been 
rmented, and tables were prepared for use in determining the original 
tavity of the beer, 7.e. the specific gravity of the worts before fermentation 
had begun. These tables, after verification by Professors Graham, 
Hofmann, and Redwood, were employed in the Revenue service until 1914, 
when they were superseded by revised ones prepared by Sir Edward Thorpe 
and Dr. Horace T. Brown, these being rendered necessary mainly owing to 
the employment in brewing of many substitutes for malt unknown in the 
earlier days. As a rapid means for determining the original gravity the 
immersion refractometer is constantly in use in the Government Laboratory. 
‘This laboratory also furnished the scientific evidence for the Inland 
Revenue Act of 1880, which enabled brewers to use a great variety of 
substances for brewing. 
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