8 KENNEL DISEASES. 
can be similarly employed, except by means of an atomizer, in the form of a 
spray. 
The most common mode of introducing medicines into the system is through 
the mucous membrane, and generally that of the stomach. They are taken in 
the solid state, as when in powders, pills, wafers, or capsules; in the form of 
mixtures, in which a solid is suspended in a liquid, or one liquid is mechanically 
mixed with another, in which it is insoluble; or in a state of solution, under 
which may be included the various forms of decoctions, infusions, wines, syrups, 
etc. For medical purposes very many drugs in common use are reduced to 
extracts. These contain much of the active principles of the substances from 
which they were obtained, the most of the inert matter having been removed in 
the process of evaporation. By this mode of concentration a very large propor- 
tion of the remedial agents can be given in the form of small pills, tablets, or 
granules; and such greatly favor convenience in the treatment of dogs, since 
they can be easily concealed and given in small toothsome morsels of meat, etc. 
When large doses are required, and of agents that are of very unpleasant taste 
or smell, they can be enclosed in wafers of rice-paper, or, better still, capsules 
of gelatin; either of which will dissolve readily, and liberate their contents in 
the stomach. In decoctions the soluble constituents of substances have been 
extracted by boiling in water. Infusions or teas are similar preparations made 
with hot or cold water, without boiling. Spirits are the alcoholic solutions of 
volatile principles, formerly, in general, procured by distillation, but now fre- 
quently prepared by simply dissolving such principles in alcohol of full strength 
or diluted. Tinctures are solutions of medicinal substances in strong or diluted 
alcohol. In fluid extracts are concentrated the active ingredients of drugs. A 
saturated solution is one that contains all of a given substance that can be dis- 
solved in the quantity of liquid used. An emulsion is a mixture of oil and 
water, made by using gum arabic, sugar, the yolk of an egg, or other like viscid 
matter. 
There are a few drugs that have a greater effect on dogs than on man; there 
are also some to which the former are decidedly less susceptible than the latter. 
Mercurials illustrate the first class, and opium, with its products, the other, — 
exceedingly large doses of that drug, which would be sure death to man, being 
often taken without any visible effect. 
Considering the relative doses of medicines generally appropriate for an adult, 
mature dogs of the largest size —as mastiffs and St. Bernards — may, as a rule, 
safely be given the same quantities; while about three-fourths of those quantities 
would be right for dogs of medium size, as setters and pointers, one-half for fox 
terriers and the like, and one-fourth for toys. 
The age is of course an important consideration in the use of drugs; puppies 
requiring much smaller doses than mature dogs to produce an equal effect, while 
the very aged cannot bear as large doses of powerful medicines as they might have 
