238 drs. t. l. brunton and j. t. cash on chemical constitution, 
large extent counteracted by lactic acid, and the subsequent passive shortening of the 
muscle under the non-balanced action of a strong solution (1 to 500) of the acid. 
On the relative action of Alkalies and Alkaline Earths on Muscle. 
We cannot enter here into a full consideration of the antagonism which certain 
members of these groups show with regard to the action of other members, but we 
may briefly state a few of the most striking facts. Thus potassium shortens the 
lengthened curves of veratria, barium (Plate 10, fig. 43), calcium, strontium, of large 
doses of sodium and of lithium (Plate 10, fig. 44), and reduces the contracture which 
they have caused. Sodium, which we have shown in large doses to cause a 
lengthened curve with increased contraction, adds to the length of calcium and 
strontium when applied in strong solutions. Barium, when it has produced its 
lengthened veratria-like curve, is, however, counteracted by almost all the substances 
which tend to produce a shorter curve. Thus calcium and potassium both of them 
lessen its altitude, and abolish its contracture. A remarkable antagonism, however, 
is that existing between rubidium and barium. The veratria-like curve which the 
former has been shown to cause when in strong solution is completely reduced by 
the application of a solution of barium, of such a strength as would, if applied by 
itself in the first instance, have caused a similar, though more extensively varied, 
curve. It is to be noted that in this antagonism, as in many others, the muscle yields 
a reaction closely similar to the normal before it develops the characteristic curve 
which is associated with the substance used to antagonise. 
With two substances of closely-allied action we sometimes find, as in the case of 
calcium and strontium, an addition of effect (Plate 10, fig. 45) without any reduction 
having taken place. It would appear that in some cases we get the two substances 
which have a similar action, at one time aiding one another, in other cases neutralising 
one another. It is hard to say what the cause of this curious result is, and any 
explanation of it must be at present entirely hypothetical. At present our data 
are too limited to allow us to formulate any general rule regarding antagonism. 
We may, however, mention some antagonisms which are at any rate curious. 
(1) Calcium reduces the barium curve to the normal, or thereabouts, before it 
causes its own peculiar form of curve. 
(2) Rubidium in strong solutions has the same effect as barium in causing a veratria- 
like curve. 
(3) Sodium usually produces with lime, not a shortening of the curve, but an 
increase of the after-action (contracture) which is often seen in the lithium muscle. 
(4) Potash lengthens the curves of didymium and lanthanum. 
(5) Lithium increases calcium effect, and calcium increases lithium effect. 
(6) Potassium opposes strontium. 
(7) We have drawn attention to the antagonism of barium to rubidium (when the 
