SHEEPWASH TOBACCO.

Press, Volume X, Issue 1191, 31 August 1866, Page 3

SHEEPWASH TOBACCO.

The following is a report by Dr. Hector upon the value, for sheepwash, of certain kinds of tobacco submitted to him for examination, contained in a Provincial Government " Grazette," issued yesterday : — Sib, —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 th 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 quartity 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 imperfeci analysis, and especially as the quality of the tobacco from different fparts oi

a package often varies considerably, sc that a small selected sample woulc 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 j a percentage 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 I - 128 per cent. Virginian grown ... 1000 „ Havannah grown ... "864 „ Maryland grown ... '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 aheepwash (which depends upon a variety of qualities, besides the mere percentage 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 bo 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 neutralized with sulphuric acid, and evaporated to dryness at 150 deg. Fah. To the residue, alcohol is added to remove the sulphate of nicotina from the sulphate of ammonia, and the alcoholic solution, evaporated carefullijr to dryness. From the weight of the nicotina salt thus obtained the percentage of nicbtina is calculated. The apparatus required consists of a glass retort and condenser, evaporating dieries, a delicate balance, sulphuric acid, alcohol, potash, and a convenient etoye. j I h£Ve the honor to be, Sir, : Tours obediently, (Signed) c James Hector. ajo John Hall, Esq., M.H.E. >:U Geological Survey Office, Wellington, July 30, 1866.

3 5 No. 7 Virginia Leaf.. 6 Cavendish ... 2 Calcutta Leaf.. 1 Calcutta Leaf. 4 Calcutta Leaf. 9 Calcutta Leaf.. 8 American S weepings.. Variety. .138 .138 .180 .485 .363 .350 .330 Not estimated Not estimated on Nicotina. Percentage Damaged form of leaf well preserved Leaf broken up Leaf broken up Large leaf, rather sandy In cake Small dry leaf, very sandy Small dry leaf, very eandy Small dry leaf, very eundy Small dry leaf, very sandy Remarks.