The "Immature Spirits (Restriction) Act, 1915," provides that no British or Foreign spirits shall be delivered for home consumption unless they have been warehoused for a period of at least three years.

This restriction on delivery, however, is not to apply to spirits delivered for duty-free purposes, nor to mixtures, compounds, etc., prepared with duty-paid spirit.

Subject to payment of duty, if imposed, the following spirits are also exempted from the restriction: -

(i) Spirits delivered to rectifiers, manufacturing chemists, perfume-makers, or other duly-licensed persons.

(ii) Spirits for scientific purposes.

(iii) Imported Geneva, perfumed spirits, and foreign liqueurs.

Nothing in the section thus summarised is to interfere with the supply of rectified spirits of wine for making medicines to medical practitioners, hospitals, and persons entitled to carry on the business of a chemist and druggist.

Additional duties are imposed by the Finance Act, 1915, on Immature Spirits which have not been warehoused, or have been warehoused less than two years. But this additional duty is not to be charged on imported mixtures which are recognised by the Commissioners of Customs and Excise as being used for medical purposes; and repayment of the additional duty is to be allowed on spirits to which the restriction on delivery does not apply, if such spirits have been used for scientific purposes or for making articles recognised by the Commissioners as articles used for medical purposes.

Increased duties were imposed on spirits by the Finance Act, 1918, the excise levy being raised to 30s. per proof gallon, or double the previous tax. But the articles indicated in the preceding paragraph are relieved from this increase, as well as from the "additional" duty mentioned.

The effect of these enactments is that alcohol used for such purposes as making perfumes need not be kept in warehouse, but if not so kept for the statutory period it must pay the additional duty as well as the full tax; whereas alcohol used in making " recognised " medicines (or for scientific purposes) is relieved from the additional duty and pays only one-half the full tax. This rebate on immature spirit therefore lowers the cost of producing spirituous medicines, and is an important matter to manufacturing chemists.

Certain articles such as tincture of orange and spirit of peppermint are not admitted to rebate, although frequently used in medicine. The reason is that they are also largely used as perfumes or flavourings, and it is impracticable to distinguish the quantities employed in medicine from those used for other purposes.

The following statistics respecting the use of industrial alcohol in the United Kingdom may be of interest. They are taken from the annual report of the Commissioners of Customs and Excise for the year 1915.

(1) Quantity of methylated spirits sent into consumption by the makers in the year 1913-14.

(2) Spirits allowed to be received in a pure state for use under the provisions of the Finance Act, 1902. Year 1913-14.

Wood naphtha ("Wood Spirit "). - This is crude methyl alcohol, containing water and various impurities, chiefly acetone and methyl acetate, but often including also small quantities of higher ketones, allyl alcohol, pyridine, amines, and other bases. It is produced by the distillation of wood, as described under "Methyl alcohol."

Various qualities of wood naphtha are made, the degree of purity depending upon the purposes for which the naphtha is required. For example, in the making of formaldehyde, and also in the colour industry, it is important to have the methyl alcohol as free as practicable from acetone; whereas a considerable proportion of acetone is admissible, and even advantageous, in wood naphtha used as a solvent for resins in making varnishes, polishes, and lacquers.

When employed as a denaturant of ethyl alcohol, wood spirit may contain a substantial proportion of acetone - varying, however with the different specifications adopted by different countries. Thus in Great Britain the maximum is 12 grams per 100 c.c, whilst in France 25 per cent, must be present. A good deal of importance attaches also to the allyl alcohol, and some to the pyridine bases, when the naphtha is required for denaturing purposes, since these compounds, though present in very small amount, help largely to make the naphtha nauseous.

In the United Kingdom the wood naphtha employed as a denaturant should conform to the following stipulations: -

(a) Not more than 30 c.c. of the naphtha should be required to decolorise a solution containing 05 gram of bromine.

(b) It must be neutral or only slightly alkaline to litmus, and at least 5 c.c. of decinormal acid should be required to neutralise 25 c.c. of the naphtha when methyl-orange is used as the indicator.

It should contain: -

(c) Not less than 72 per cent. by volume of methyl alcohol.

(d) Not more than 12 grams of acetone, aldehydes, and higher ketones per 100 c.c, estimated as " acetone " by the formation of iodoform according to Messinger's method.

(e) Not more than 3 grams of esters per 100 c.c, estimated as methyl acetate by hydrolysis.

The detailed description of the examination of wood naphtha in respect of these tests, together with some explanatory remarks, is given below.