556 
ME. J. PEIESTLEY ON THE PHYSIOLOGICAL ACTION OE VANADIUM. 
Fig. 3. Curves of muscular contraction in the cases of a normal frog ( b , V ) and of two 
frogs poisoned by subcutaneous injection of vanadate of sodium (a, a' and c, c 1 ), 
to illustrate Exp. LXXIX., wherethe method of obtaining them is described. 
a, a ', with muscles of poisoned frog 4 hours after "poisoning. Maximum 
stimulus was employed (secondary coil close up to primary). 
Making. Breaking. 
Time of whole contraction -11 second. ’ll second. 
Time of latent period '015 „ '0075 „ 
Time of maximum contraction *0725 „ ' 07 „ 
b, b\ with muscles of normal frog 2 hours after decapitation. Maximum 
stimulus was employed (secondary coil close up to primary). 
Making. Breaking. 
Time of whole contraction *105 second. ’105 second. 
Time of latent period '0075 „ '005 „ 
Time of maximum contraction '0625 „ ’ '065 „ 
c, c 1 , with muscles of poisoned frog 4 hours after poisoning. Maximum 
stimulus was employed (secondary coil close up to primary). 
Making. Breaking. 
Time of whole contraction T15 second. '1125 second. 
Time of latent period -0125 „ '01 „ 
Time of maximum contraction '08 „ '065 „ 
Fig. 4. Curves of muscular work in the cases of a normal frog ( b ) and of two frogs poisoned 
by subcutaneous injection of vanadate of sodium ( a and c ), to illustrate 
Exp. LXXVIII., where the method of obtaining them is described. 
a , with muscle of poisoned frog 1^ hour after poisoning, when para- 
lysis of motion was fully developed. Maximum stimulus was employed 
(secondary coil 5 centims. from primary). 
b, with muscle of normal frog soon after decapitation. Maximum stimulus 
was employed ‘(secondary coil 5'5 centims. from primary). 
c, with muscle "of poisoned frog 5 hours after injection of poison, and 3 
hours after paralysis of motion was fully developed. Maximum stimulus was 
employed (secondary coil close up to primary). 
Fig. 5. To illustrate Exp. LXXX. The continuous line represents the variation in 
blood-pressure, the outside vertical column of figures at each end of the Table 
indicating the blood-pressure in millims. of mercury, while the times are given 
by the row of figures ( = minutes) along the bottom of the Table. The dotted 
line traces the variation in rapidity of respiration, the inside vertical column 
of figures at the left end of the Table giving the number of respirations in 10 
seconds, while the times, as before, are given by the figures at the foot. 
Fig. 6. To illustrate Exp. LXXXI. The explanation of the preceding figure applies 
to this also. — Note. The rise of blood-pressure indicated by the (*) was accom- 
panied by struggles ; at the same moment the rabbit’s trachea happened to 
be disconnected from the apparatus for registering respiration (see p. 535) ; 
hence it is impossible to say whether or not an increase in rapidity of 
breathing occurred which should have been recorded at ( X )• 
