224 DRS. t. l. brunton and j. t. cash on chemical constitution, 
two sub-groups :— (a) containing beryllium, calcium, strontium, and barium; and 
(6) containing yttrium, didymium, erbium, and lanthanum. 
In group (a) we notice a tendency to increased reflex action. In this particular it 
agrees with ammonium, but differs from members of the alkaline group. We have 
already noted that, in some members of the alkaline group, a slightly increased reflex 
action might be observed at the commencement of the poisoning, but this is consider¬ 
ably less than in the case of most of the members of group (a), with the exception of 
barium. Excitement of the spinal cord is most marked in poisoning by beryllium; 
next come strontium and calcium; and lastly barium, in which excitement, if present 
at all, is very slight. 
In group (b) reflex action in the cord is not increased, nor does it appear to be very 
much diminished till the last. In this group, however, the higher centres appear to be 
paralyzed. We infer this from the fact that yttrium greatly diminishes co-ordinating 
power in the Frog, rendering the movements ataxic, and causing the animal to lie with 
the legs fully stretched out, although neither muscle or nerve is paralyzed. Didy¬ 
mium, erbium, and lanthanum all have a similar action. 
In regard to their action on motor nerves, we notice the same well marked division 
into two groups as in their general action : beryllium, calcium, strontium, and barium 
all paralyzing the motor nerves to some extent. Lanthanum has also a paralyzing 
action, but yttrium, didymium, and erbium have non6. In this respect these three 
bodies agree with sodium and rubidium, and differ from all the others belonging to 
these two groups which we have examined. 
In regard to their action upon muscle, we do not find that these bodies can be 
so readily subdivided into two well marked sub-groups. 
The contractility of muscle, as shown by the height of the curve, is greatly increased 
by barium (Plate 8, fig. 15, a-cl), and occasionally, to a small extent, by erbium 
(Plate 8, fig. 16, a, b) and lanthanum (Plate 8, fig. 17, a, b). It is sometimes 
increased and sometimes diminished by yttrium (Plate 8, fig. 18, a, b) and calcium 
(Plate 8, fig. 19, a, b, c). It is diminished by didymium (Plate 9, fig. 20, a, b), 
strontium (Plate 9, fig. 21, a, b, c ), and beryllium (Plate 9, fig. 22, a, b; fig. 23, a, b). 
We have found that the small variations occurring in the extent of contraction are 
best observed when the poison is applied locally in the form of solution. Where the 
muscles have been examined of an animal completely poisoned with the substance, the 
ultimate, rather than the primary result, is obtained. 
The duration of the contraction, as shown by the length of the curve, is increased 
by barium, calcium, strontium, yttrium, and erbium. It is unaffected, or slightly 
diminished, by beryllium, didymium, and lanthanum (see figs. 17, 20, 22). It is obvious 
that the action of the rarer metals beryllium, erbium, didymium, lanthanum, and 
yttrium is but feeble in any direction when compared with the effect of calcium, &c. 
The contracture is increased by barium, calcium, strontium, yttrium, and beryllium. 
