ME. J. PEIESTLET ON THE PHYSIOLOGICAL ACTION OF VANADIUM. 497 
of vanadium compounds, it was found expedient to restrict the investigation to the 
sodium compound of vanadic acid. The reasons for not examining the action of the lower 
oxides, or of the compounds analogous to them, were : — First, that definite solutions 
could not he obtained in such a condition as to admit of their being suitably introduced 
into the animal organism ; this remark will be understood when it is stated that no 
useful results can be obtained from experiments in which a very alkaline or a very acid 
solution, capable of at once altering the chemical and physical properties of the blood, 
is introduced into that fluid. Second, that the lower oxides of vanadium are so 
extremely unstable as to render any experiments with them very difficult of interpre- 
tation. Fortunately we may, with reason, conclude that an elaborate investigation into 
the mode of action of any soluble vanadate will fairly represent the physiological action 
of the vanadium^ compounds generally ; for although the lethal doses may he, and often 
are, different, the physiological properties of any of the inorganic compounds of a 
poisonous metal appear to be similar, whatever the nature of the compound. 
The salt used in this research was the tribasic sodium vanadate (Na 3 V0 4 ), obtained 
by fusing a mixture of three molecules of sodium carbonate with one molecule of vana- 
dium pentoxide until no further evolution of carbonic acid occurred. The tribasic 
sodium vanadate resulting from this operation is a white crystalline mass, easily soluble 
in water. The solution employed throughout this research contained exactly five per 
cent, of V 2 0 5 . In order to avoid any accidental presence of sodium carbonate which 
might exert an injurious action on the blood of the animal experimented upon, a stream 
of C0 2 was passed through the concentrated solution of the sodium salt before it was 
diluted so as to have the required strength. The solutions employed were prepared 
from time to time in the Chemical Laboratory of the Owens College, under the super- 
vision of Professor Koscoe. 
In this paper the mode of action of vanadium on simple organisms and on animals 
of different classes will be described, and then the experiments which illustrate its more 
precise influence on the various functions of the body will be given in detail. 
It was originally intended to institute in this memoir a comparison between the 
action of vanadium and that of the allied metals of the same family. However, we do 
not yet possess sufficiently elaborate accounts of the precise physiological action of 
these metals, so that further investigations are necessary before such a comparison can 
be usefully instituted. Such an investigation is now in progress in the Physiological 
Laboratory of the Owens College. A research which the author has lately carried out 
on the physiological action of chromium appears to prove most conclusively that this 
metal, whose atomic weight, as was just mentioned, is almost identical with that of 
vanadium, exerts an altogether different physiological action and possesses a less intense 
poisonous activity. 
JIDCCCLXXVI, 
3 z 
