494 TRANSACTIONS OF THE 



as to enable the observer, by means of the microscope, at once to 

 distinguish tobacco in all the forms of cut and roll tobacco, and 

 even when the leaf is still more minutely divided, as in some 

 kinds of snufif. The gum of the tobacco is composed chiefly of 

 chlorides, sulphates, carbonates, and phosphates, combined with 

 much lime, leaves of tobacco, when burned to an ash, are re- 

 markable for the large amount of soluble salts which they con- 

 tained. The common adulterations of tobacco consist in the 

 addition of water, sugar, and salts, and the presence of these can 

 only be declared with certainty, when they are in considerable 

 excess. 



Fifty-eight samples of cigars were examined. Some of them 

 were made up of liay and brown paper, but in the majority of 

 cases tl^y were entirely of tobacco. 



From their examination of 43 samples of snufif of different kinds, 

 the conclusions were, that chloride of sodium or salt is added in 

 large and very variable quantities, to all descriptions of snufif, 

 ranging from 1 to 18 per cent. That the alkaline and earthy 

 carbonates, chiefly of potash and lime, are likewise added to snufif, 

 sometimes in large quantities, l)ut usually to a less extent than 

 chloride of sodium. In some cases alkaline and earthy phos- 

 phates and sulphates were in excess. That oxide of iron derived 

 from different descriptions of colored ferruginous earths, as red 

 ochre, yellow ochre, and some of the brown earths, as umber, 

 was present in upwards of two-thirds of the samples; and all the 

 Scotch snuffs contained iron; chromate of lead was detected in 

 eighteen of the samples. The presence of this metallic compound 

 in snuff constitutes an adulteration. Bi-chromate of potash was 

 present in three samples, and silica in several. In most of the 

 silicious residues of the ashes shining particles were observed, 

 which, under the microscope, presented all the appearances of 

 powdered glass. The average proportion of water in the moist 

 snuffs was about 25 per cent. Looking, then, at the whole of the 

 above results, it is evident that snufif is subject to a very large 

 amount of adulteration, and tliat of a kind wliich is not only 

 detrimental to the revenue, but highly injurious to health. The 

 addition of water to tobacco and to snufif, constitutes a very 

 important means of adulterating it. Many of the articles that I 

 have mentioned, which are not poisonous in themselves, would be 

 very prejudicial if taken up through the nostrils to the brain. 



From the examination of upwards of one hundred samples of 

 colored sugar confectionary, the following important conclusions 



