312 
ON THERAPEUTICS. 
every available source supplies the loss, and reaction of 
various degrees of force occurs; the repetition of the opera¬ 
tion sufficiently often to continue the depression is impossible, 
on account of the important nature of the fluid rendering its 
repeated removal productive of very serious consequences, 
and hence bloodletting is only justifiable when an immediate 
effect upon the circulation is necessary. 
In any form of local hyperaemia, the withdrawal of blood 
may effect a restoration of the balance of circulation, not by 
removing blood directly from the part, but by generally 
diminishing the volume of the fluid, and lessening the energy 
of its flow, and allowing time for the removal of the local 
excess by the veins. It is found that repeated bleedings 
occasion the diminution of the red particles of the blood, and 
the increase of the fibrinous element, thus in two ways, at 
least, impairing its constitution. Another peculiarity con¬ 
nected with periodical bleeding is the occurrence of symptoms 
of plethora, or fulness, if the operation be postponed beyond 
the usual time, not merely at certain seasons of the year, 
which might account for a particular condition of system, but 
in cases where the operation has been performed systemati¬ 
cally at frequent intervals; this tendency on the part of the 
organism to accommodate itself to a certain course of un¬ 
natural treatment, is frequently exemplified in a variety of 
instances. 
The principal objection to bloodletting under ordinary cir¬ 
cumstances, seems to be the absence of a direct necessity for 
such treatment, save in those decided cases of local excess 
where an immediate cessation of the supply is desirable. 
When the indications are not urgent, other sedative agencies 
answer the same end, generally more perfectly; and hence 
the present disfavour in which the operation is held arises in 
a measure from a natural and well-founded dislike to the 
performance of an operation, however simple, which is not 
required, and which may be efficiently represented by less 
energetic methods of treatment. It seems to us unlikely that 
venesection will ever again attain its former place among 
scientific practitioners, but to the unlearned it offers a ready 
though coarse means of effecting what their ignorance of 
therapeutics does not enable them to effect in any other way. 
Bleeding we believe to be advisable, not indispensable, in 
acute inflammation, and congestion, but it can hardly be 
defended under any other circumstances, presuming the 
surgeon to have unlimited command of medicinal agents. 
Hydrocyanic acid is not much used in English veterinary 
practice; physiologically its action is narcotic, but introduced 
