484 The Physiological Position of Tobacco. [O&tober, 
the excitability of the nervo-motors when the doses were 
feeble. Sensibility is only affected by very large doses. 
When a strong solution of nicotine is injected under the 
skin of a frog, galvanism has little or no effect upon the 
nervo-motors. ‘The effect is most noticeable on the nerves 
nearest the wound. 
From this he concludes that the paralysis is caused less 
by the circulation than by absorption across the tissues. 
This he tested further, by tying with ligatures one of the pos- 
terior members of a frog, leaving only the blood-vessels and 
nerves free, so that the poison could only reach the nerves 
by the circulation. Some nicotine was then injected sub- 
cutaneously into another member. ‘The poisoned limb did 
not respond to electrical excitement, but the one which bore 
the ligatures was evidently sensible to it, though not to the 
normal degree. 
The action of nicotine upon the iris is well known, yet 
whilst some consider it to produce dilatation, others affirm its 
effect to be contraction. ‘The iris is composed of two orders 
of muscular tissue. The circular fibres influenced by the 
motor oculi, and the radiating fibres obeying the great sym- 
pathetic, perform the two functions of the iris, dilatation and 
contraction. ‘The stimulation of the third pair of nerves 
causes a contraction of the pupil; a larger dose of nicotine 
destroys its susceptibility and dilatation follows, the upper lid 
falls, strabismus ensues, the eyeball becomes fixed—in short, 
the motor power of the eye is paralysed. M. Blatin con- 
siders that the muscular fibre of the eye is not at all affected 
by the poison. 
To determine the influence of tobacco upon the secretions, 
he made some experiments upon a dog, to which small doses 
of nicotine were daily administered. An increased dryness 
of the mucous system and a large secretion of urine were 
the first result. A wound made on its leg had not cicatrised 
in eight days, in spite of the well-known rapidity with which 
wounds usually heal in dogs. The mouth became dry, the 
throat inflamed, the animal, although constantly drinking, 
was unable to quench its thirst. Some drops of water 
placed upon the wound moistened it only a few moments. 
As the pressure of the blood is increased by this poison, in 
small doses it is a diuretic. 
From all these experiments we may conclude that nico- 
tine acts both on the heart and vessels, and is a vasculo- 
cardiac poison. 
Blatin proposes to divide tobacco poisoning into two 
classes, acute and chronic. The first is the result of a large 
