864 
POPULAE .SCIENCE EE VIEW. 
which is merely a fine variety of soot, simply attaches itself to the mucous 
membrane of the mouth, throat, and possibly air-passages, rendering them 
of a blackish hue, which, after increased development of epithelium, becomes 
thrown off ; this is, therefore, not a very injurious element. The ammonia 
comes next ; it is the material which parches the mouth of the smoker, 
stimulates the salivary glands to action, and which produces that feeling of 
drought that renders it a familiar saying that “ smoking leads to drink- 
ing.” These, according to Dr. Richardson, are not its only effects : it 
produces an alteration of the blood by operating upon the blood globules ; 
these become shrivelled at their edges, and the whole blood becomes more 
liquid. This is a serious assertion. We do not mean in so far as it 
touches on the action of tobacco smoke tout entier upon the blood, but inas- 
much as it refers the liquefying and impoverishing action to the ammonia. 
The writer some years ago produced an admirable essay upon “ The Cause of 
the Coagulation of the Blood,” in which the view was advanced that the 
fibrine of the vital fluid is kept in a state of solution by the influence of 
ammonia, and that when blood was drawn from the body the ammonia 
evaporated, and the fibrine assumed the solid form. May it not be that he has 
effected too close an application of this theory to the case now in point ? 
We really cannot see that he is fully justified in attributing the blood-changes 
to the quantity of ammonia inhaled by the smoker. However, as we our- 
selves have made no experiments upon the subject, our remarks are only 
intended to be suggestive. The carbonic acid, which is produced in consi- 
derable quantity, is supposed by the author to cause those sensations of 
sleepiness and lassitude which follow the prolonged inhalation of tobacco 
fumes. The water cannot be productive of any decided action. The od, 
— which is familiar to every smoker as the substance which eventually gives 
his pipe that colour which is so highly prized by those who indulge a fancy 
for “ meerschaums,” — ^being compounded of three different principles, it be- 
comes necessary to consider the effect of each of these separately. The 
volatile element is that which gives rise to the unpleasant odour of a bad 
form of tobacco, and the delicious perfume of a good cigar. This it is, too, 
which, in its partially decomposed condition, hangs about the clothes of a 
smoker, and about the curtains of the room in which he indulges what some 
consider his vicious propensity. It may be said to cause no injurious effects 
upon the body. The two other substances are, without doubt, those which in 
excess are productive of the marked poisonous action of the plant. These 
differ not only in physical character, but in physiological action ; there is, 
too, a distinction to be drawn as to the frequency with which their action is 
exhibited. The bitter principle, though causing a more immediately unplea- 
sant result than the alkaloid, has no such dangerous qualities as the latter. 
It is a resinous substance, which gives to the cigar or tobacco its flavour, and 
which is so largely present in those specimens of the weed which the tobac- 
conist terms strong cigars, as distinguished from mild ones. Its action is 
upon the stomach, which it stimulates to reverse peristaltic movements, 
thereby producing in some cases, especially in young smokers, violent 
vomiting. It must not be inferred from this that it has simply a direct 
action on the stomach : we presume, though Dr. Richardson does not say so, 
that it operates on the digestive sac through the pneumogastric nerve ; for 
