October 29, 1870.] 
THE PHARMACEUTICAL JOURNAL AND TRANSACTIONS. 
311 
RATIONAL THERAPEUTICS. 
In the introduction to a course of lectures just 
commenced, Dr. Richardson treated of the method to 
be followed in studying the relation between re¬ 
medies and their effects, illustrating the connection 
between variation of physiological power and varia¬ 
tion of chemical constitution by reference to the 
ethyl compounds. The radicle ethyl furnishes a 
multitude of compounds that are analogous in pos¬ 
sessing narcotic power; commencing with the hydride 
H* * s * n com position least removed from 
the radicle itself, we find it is a gas, insoluble in 
blood and negative in its action on nervous material; 
hence it is not active either as an excitant or as a 
narcotic. It must be inhaled with air in the propor¬ 
tion of 30 or 40 per cent, in order to produce any 
decisive effect. Then it acts like nitrogen, producing 
temporary insensibility by interfering with the re¬ 
spiratory process, which cannot be sustained. 
U XT l 
Again, alcohol 2 jj 5 j 0 (which differs from hy¬ 
dride of ethyl by containing oxygen and from water 
S ]• 0, in having ethyl in place of half its hydrogen) 
Hj 
is a stimulant and narcotic. It acts directly on the 
nervous system and excites the action of the heart. 
Given freely it induces deep narcotism, but as it is 
largely absorbed by the blood, a great quantity of it 
is required before there is sufficient saturation to in¬ 
duce narcotism. Hence it is not difficult to make an 
annual insensible with alcohol vapour. 
Replacing the whole of the hydrogen in water by 
ethyl, we obtain ether, q- 2 jj 5 j0, a powerful narcotic, 
having less direct stimulating action than alcohol, 
but producing its effects more rapidly. Being less 
soluble in blood than alcohol, it may be administered 
by inhalation of its vapour so as to saturate the 
blood, and then it acts as a narcotic. Still it is too 
soluble, and is, therefore, wanting in potency, so that 
we are obliged in using it to keep up the saturation 
by persistent administration to the exclusion of much 
ah. Thus symptoms of asphyxia and restlessness 
are often produced, which prevent the use of ether. 
In the chloride of ethyl, C 2 H 5 Cl, we have a sub¬ 
stance which produces great excitation of the heart 
and deep narcotism. Being sparingly soluble in blood 
the saturation necessary for this effect is soon reached. 
But like chloroform, which it resembles chemically, 
this substance produces rigid muscular contraction 
as it narcotizes; it also causes vomiting, and, by 
arresting first respiration, then the action of the 
heart, it kills, as chloroform does, when its adminis¬ 
tration is continued too long. 
The iodide of ethyl produces with narcotism great 
excitement of the heart and circulation as well as 
free glandular secretion. 
_ Bromide of ethyl, C 2 H 5 Br, possessing good phy¬ 
sical qualities for a volatile narcotic, produces deep 
narcotism and but slight muscular excitement, 
though to some extent, like the chloride and iodide, 
it excites, causes vomiting and irritates the mucous 
surfaces. 
0 TL 1 
Sulpliide of ethyl, ^, 2 ^ - S, produces rapid narco¬ 
tism without excitement, and though with frogs the 
insensibility may be sustained for many hours with¬ 
out death, it induces paralysis of the nervous centres 
supplying the heart and the muscles of respiration. 
Third Series, No. 18. 
Nitrite of ethyl, C 2 H 5 N0 2 , produces, besides nar¬ 
cotism, a general paralysis of the nerves governing 
the contractile function of the blood-vessels, causing 
suffusion of the face, and rapid action of the heart. 
A similar series of relations between constitution 
and physiological action is found in the amyl series. 
Between the actions of the ethyl and amyl series there 
is a difference in regard to what Dr. Richardson calls 
persistency of effect, due, he considers, to the radicle 
amyl being richer in carbon and hydrogen. 
Dr. Richardson ascribes the narcotism in all 
these cases to the ethyl of the several compounds, 
and the phenomena which lie outside the narcotism 
he considers to be referable to the various other sub¬ 
stances with which it is combined. He considers 
that wherever a basic element or radicle exists it 
always plays a part of its own, at the same time 
modifying the action of the substances with which 
it may be united but not destroying their action or 
preventing them from being recognized. But in some 
cases the action of the associated substance may be 
so determinate that it becomes the prominent fact, 
while the action of the base is obscured. This is to 
some extent the case with the nitrites, and very 
markedly so in the case of the cyanides. 
The physical properties of a substance probably 
modify the physiological action belonging to its con¬ 
stituents ; thus vapour density will regulate the rate 
of diffusion; the boiling-point, solubility and other 
characters will also exercise some influence in modi¬ 
fying the effects of a substance as a medicine. 
We must also admit the probability that some 
medicines undergo chemical alteration within the 
body. Thus, for instance, hydrate of chloral is per¬ 
haps converted into chloroform by contact with weak 
alkaline liquids in the organism. 
Again, though animals are, as a rule, affected in 
like manner by various substances, there are pecu¬ 
liarities in some animals in consequence of which 
the effects of certain substances are modified in par¬ 
ticular cases. Pigeons are insensible to the influ¬ 
ence of morphia, goats are unaffected by nicotine. 
The specific action of substances is another point 
to be studied. Of late years it has been customary 
to suppose that all agents act through the blood; but 
we are now learning that many substances act directly 
upon the peripheral nerve-surfaces, the effect being 
transmitted by light or sound. Dr. Richardson con¬ 
siders that nitrite of amyl acts thus, for in an animal 
recently dead the heart can be influenced by its 
application to the surface of the retina, or to the olfac¬ 
tory tract. Dr. James Jones has also shown that 
prussic acid acts fatally by application to the medulla 
oblongata. 
The study of this subject leads to ground so 
entirely new that it cannot easily be traversed, - but 
having got a glimpse of what is to be learnt it is, as 
Dr. Richardson remarked, impossible to leave such 
ground untraversed. “ Better get over it ever so 
little, and even in lame and shambling gait than-not 
to venture at all. Let us once fairly get upon this new 
ground and we march straight to the positive science 
and art of cure ; then the fate of quackery intra or 
extra the ranks, is sealed for ever. Let us not ven¬ 
ture on the new ground, and we remain as we are— 
■wiser than gross uncertainties but weak because, 
uncertain ourselves, we are constantly obliged by 
our questionings and admissions to proclaim to the 
vulgar that even the guides cannot find their way. 
