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NICOTIANA TABACUM. ORD. XII. ‘Solanacee, seu Luride. 211 
“ By this combination of qualities, all the effects of tobacco may 
“ be explained ; but I shall begin with considering its effects as they 
appear in the use of it as an article of living. 
“ As such it has been employed by snuffing, smoking, and chew- 
ing; practices which, as having been for two hundred years past 
“common to all Europe, need not be described here. Like other 
narcotics, the use of it may be introduced by degrees; so that its 
“ peculiar effects, even from large quantities employed,’ may not, 
* or may hardly at all appear: but this does not at all contradict 
“the account I have given of its quality with respect to persons 
“unaccustomed to it, and even of its tendency to show its power in 
** those much accustomed to it: for even in these, the power of habit 
“ has its limits; so that in persons going but a little beyond the 
* dose to which they have been accustomed, = Sey; violent effects are 
* sometimes produced. ~~~ sai a cian: 
On this subject it is to be remarked, that the power of habit is 
« often uhequal; so that in persons accustomed to the use of tobacco, 
“a lesser quantity than what they had been accustomed to, will 
“ often have stronger effects than had before commonly appeared. 
“I knew a lady who had been for more than twenty years accus- 
“ tomed to take snuff, and that at every time of day; but she came 
© at length to observe, that snuffing a good deal before dinner took 
“ away her appetite: and she came at length to find, that a single 
pinch, taken any time before dinner, took away almost entirely 
“her appetite for that meal. When, however, she abstained en- 
“ tirely from snuff before dinner, her appetite continued as usual; 
“and after dinner, for the rest of the day, she took snuff pretty 
«“ freely without any inconvenience. 
“ This is an instance of the inequality of the power of habit in 
“ exerting its effects: but in what cases this may take place, we 
“cannot determine, and must now go on in marking its usual and 
“ ordinary powers. When snuff, that is, tobacco in powder, is first 
“applied-to the nose, it proves a stimulus, and excites sneezing; 
“but by repetition that effect entirely ceases, 
