518 ME. J. PEIESTLEY ON THE PHYSIOLOGICAL ACTION OE VANADIUM. 
Lethal Lose. 
From the preceding experiments on rabbits the m ini mum lethal dose of vanadic pent- 
oxide in the form of sodium vanadate was determined for those animals. 
In Exp. XX. a rabbit weighing 1449 grammes had sodium vanadate subcutaneously 
injected containing 5 milligrammes V 2 O s . The rabbit recovered; that is to say, 
3'45 milligrammes V 2 0 5 per kilogramme of rabbit are insufficient to cause death. 
In Exp. XVIII. a rabbit weighing 1705 grammes was injected subcutaneously with 
a similar solution containing 25 milligrammes V 2 O s . The rabbit died ; therefore 
14-66 milligrammes V 2 0 5 per kilogramme of rabbit are sufficient to cause death. 
A rabbit was taken weighing 2720 grammes (it was the same rabbit as had recovered 
four days previously from the injection 'per rectum of 150 milligrammes V 2 0 5 ; see Exp. 
XXXII.). A solution of sodium vanadate was prepared containing 25 milligrammes 
V 2 0 5 , i. e. 9T8 milligrammes per kilogramme of rabbit, and injected subcutaneously. 
Marked symptoms of poisoning occurred — rapid respiration, sluggishness, rocking of 
head, partial paralysis and weakness, which lasted for about an hour and a half ; after 
which the rabbit became rapidly normal, and completely recovered. 
It was deemed unnecessary, in the case of a body like vanadium, to sacrifice more 
rabbits in order to fix with greater exactness the lethal dose. The minimum lethal dose? 
therefore, lies between 14-66 milligrammes and 9-18 milligrammes of V 2 0 5 per kilo- 
gramme of rabbit. 
Lesume of the General Action of Vanadium. 
A review of the experiments on the general action of sodium vanadate on the animal 
economy displays two well-marked modes of action, by either of which, or by both 
combined, the poison may produce death. The first, an action on the nervous system, 
takes in frogs the form of gradual paralysis, first of respiration, and afterwards of motion 
generally ; and in pigeons, guineapigs, rabbits, and cats, of drowsiness, or indifference 
to external circumstances, together with partial paralysis and convulsions affecting some 
or all of the muscles of the body. The second, an action on the alimentary mucous 
membrane, exists in frogs only in cases of slow poisoning, and is evidenced by congestion 
of the interior of the alimentary canal. In pigeons, in which, when the dose of the salt 
has been small, it precedes the nervous symptoms by some hours, it is evidenced by the 
discharge of sanguinolent fluid faeces during life, and after death by the congested con- 
dition of the alimentary mucous membrane and the quantity of mucous contents of the 
intestine. In guineapigs, in which, on the contrary, the nervous symptoms are more 
important, congestion of the alimentary tract (which is especially noticeable when the 
dose of poison has been small) sufficiently attests the presence of intestinal mischief. 
Tn rabbits, again, the nervous affection is more prominent, and in the majority of cases 
is clearly the proximate cause of death. But in their case, as in that of guineapigs, 
signs of congestion in the intestines, and the presence in them of quantities of glairy 
fluid after poisoning, prove the existence of irritation. In the case of dogs the doses 
