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Provincial Secretary’s Office,
Christchurch, August 28, 1866.

HIS Honor the Superintendent directs the publication of the following Report, by Dr Hector, upon the value, for Sheep-wash, of certain kinds of Tobacco submitted to him for examination.

F. E. STEWART,
Provincial Secretary.

To JOHN HALL, Esq., M.H.R.
Geological Survey Office,
Wellington, July 30, 1866.

SIR— I beg to furnish you with a few notes respecting the value of the various samples of tobacco which you forwarded to this laboratory for examination.

The investigation is to be continued so as to include several other samples of tobacco, and among others, tobacco grown in different parts of the Australian Colonies and New Zealand.

I assume that the active poisonous principle on which the efficacy of the tobacco-wash for sheep depends, is the Alkaloid Nicotina, an acrid volatile oil, soluble in water, which exists in different samples of tobacco in the proportion of 3 to 11 parts in the 1000 part of the dry leaf, the remainder consisting of water, gum, resin, ligneous tissue, and bitter extractive matter.

The accurate estimation by chemical analysis of the quantity of nicotina in tobacco, is an extremely delicate and tedious process, and I think that for all practical purposes the inspection of the sample by a person skilled in judging of tobacco, will give more reliable results than an imperfect analysis, and especially as the quality of the tobacco from different parts of a package often varies considerably, so that a small selected sample would probably give very different results from operations on a large scale.

The following estimate of the quantity of Nicotina in the samples submitted may be considered as tolerably accurate as far as their relative proportion, but the total quantity contained in the sample in each case is probably somewhat higher than stated.

Samples 3, 5, and 8 had been damaged by the Customs officers, with spirit of tar, but before concluding that this is the reason for their containing so low a per centage of nicotina, samples of the same tobacco, before being damaged, should also have been examined.

It is, however, very probable that the spirit of tar does cause the volatilisation of the active principle of the tobacco in addition to the bad effect it exercises on the structure of the leaf by which it is rendered less capable of forming a decoction by simple boiling with water.

The usual proportion of nicotina in different kinds of tobacco is given in chemical works as follows:—

French grown ... 1·128 per cent.
Virginian " ... 1·000 "
Havanah " ... ·864 "
Maryland " ... ·528 "
Tobacco prepared for smoking ... ·386 "

Although I cannot recommend any process that could be adopted with ease for testing the quality of the tobacco for sheep-wash, (which depends upon a variety of qualities, besides the mere per centage of nicotina it contains); my assistant Mr. Skey, has suggested the following as a process which if carefully performed will give approximate results, though not strictly accurate, without much expense, time, or special skill being required.

The tobacco is first cut up into small fragments, and digested for twelve hours in water acidulated with sulphuric acid. The decoction so obtained is then rendered decidedly alkaline with potash, and transferred to a retort provided with a good condensing apparatus, and distilled to dryness.

The distillate must then be neutralised with sulphuric acid, and evaporated to dryness at 150° F.

To the residue alcohol is added to remove the sulphate of nicotina from the sulphate of ammonia, and the alcoholic solution evaporated carefully to dryness.

From the weight of the nicotina salt thus obtained the per centage of nicotina is calculated.

The apparatus required consists of a glass retort and condenser, evaporating dishes, a delicate balance, sulphuric acid, alcohol, potash, and a convenient stove.

I have the honor to be,

Sir,

Your’s obediently,

(signed) JAMES HECTOR.

CHRISTCHURCH :
Printed, under the authority of the Provincial Government of the Province of Canterbury, at the ‘Press’ Office, Cashel-street, by JAMES EDWARD FITZGERALD, Official Printer for the time being to the said Government.