moiroud’s veterinary materia medica. 463 
M. Moiroud proceeds to the Second Class of General 
Stimulants; —medicines which tend to augment the contracti¬ 
lity of the fibres, and, in consequence, to strengthen the tissue of 
the organs, without producing any marked astringent effect, and 
designated as tonics and strengtheners. These medicines principally 
exercise their influence on the insensible movements of the inti¬ 
mate tissue of the living parts, and which are the result of that 
power called by physiologists tonicity ; and thence the term tonic. 
The word strengthener expresses a secondary effect, more va¬ 
riable and more uncertain, and which may be in many therapeuti¬ 
cal agents essentially different. 
Tonics augment the elasticity of the tissues, and render them 
stronger and more contractile, without increasing their sensibility 
or raising their temperature. Their action, at first confined to 
the parts to which they are applied, gradually extends over the 
whole frame, if their use be persevered in. 
Being taken into the stomach, their first effect is to excite the 
appetite, to augment the energy of the organs of digestion, and 
to render that function more rapid and more complete, the intes¬ 
tinal absorption more active, and the fa3ces of greater consistence, 
and less frequently expelled. This first impression is extended 
by sympathy and absorption, and the heart acquires new ener¬ 
gy—the pulse becomes fuller and stronger, and the respiration is 
deeper. The assimilation of the food becomes more completely 
effected—the blood richer, and the nutrition more abundant: 
the absorption is also increased, not only in the mucous surface 
of the alimentary canal, but in the meshes of the cellular tissue, 
and the great abdominal cavities: therefore tonics are indicated 
in certain chronic dropsical complaints, and in infiltration of the 
subcutaneous tissue. The secretions are also affected: they are 
rendered more regular and healthy. No appreciable physical 
change is produced by tonics on the tissues, or it is only by their 
influence on the vital powers that we recognise their agency. 
Tonics are indicated in all diseases essentially connected with 
debility, and in those that are accompanied by a prostration of 
strength, as in certain stages of typhoid complaints. Although in¬ 
termittent fever is little known in veterinary medicine, the anti¬ 
periodical power possessed by tonics is useful to prevent those 
returns of exacerbation which accompany some maladies of do¬ 
mestic animals. They are also useful in the advanced period of 
catarrhal affections, in chronic irritations, and in the weakness 
which so often accompanies the stage of convalescence. 
Even when lowered they are injurious in acute inflammation, 
in some nervous affections, and in those chronic irritations which 
are accompanied by much pain. 
