92 ROYAL SOCIETY OF CANADA 
known, the complete removal of the ovaries results in menopause. It 
may be, that like the other ductless glands, the ovaries possess a similar 
power of accelerating calcium metabolism and the excretion of these 
salts. It is, of course, too much to claim, that the calcium metabolism 
in the body is the all in all in determining the nature and direction of 
the processes of growth or of retrogression, or that it is the sole factor 
in regulating sexual functions, but I think that I have adduced enough 
evidence to show that it is at least of prime importance. 
Passing on to the next point, the question of blood pressure, I will 
in a few words recapitulate the main facts. The general systemic 
blood pressure depends first upon three things; the strength of the 
heart muscle, the tonus of the arteries, and the character and amount of 
the contained blood. A powerfully acting heart will raise blood pressure, 
a contracted state of the arteriolar wall will raise blood pressure, a con- 
dition of plethora, or the presence of certain toxic substances in the 
blood, will raise blood pressure. The contraction of the heart and the 
size of the blood vessels is under the control of the vasomotor nerves. 
I would emphasize that the character of the circulating blood and the 
contractile power of muscle are only two of the factors in the regulation 
of blood pressure. In studying the effect of calcium upon the circulation 
we must consistently remember this. 
I have very little information on the relationship of calcium to 
blood pressure. It is stated that it leads to vaso-constriction, and this 
in itself would naturally increase blood pressure. It is also stated that 
a distinguished clinician in London makes use of lime as a cardiac tonic. 
I have not as yet come upon much experimental work bearing upon this 
question. Bell and Hick, found that calcium raised blood pressure, 
though not to the same extent as extracts of pituitary or adrenal.! I 
should judge, however, that observations should be made on the human 
subject if we are to get reliable information, for the blood of the rabbit, 
the animal ordinarily used for experimentation contains much more 
lime than does the human being, so that the results will not be strictly 
comparable. I would cite an experiment on myself, which may be 
taken for what an isolated observation is worth. The time chosen was 
about eleven o’clock a.m. when the process of digestion was nearly 
over, for it is held that if calcium is taken when the stomach is full of 
food its effects are largely neutralized. My blood pressure at the time 
was 132 (with the Riva-Rocci instrument). I then ingested 60 grains 
of Merck’s calcium lactate. Three-quarters of an hour later my blood 
pressure was 134. This interval of time was chosen because Sir A. E. 
Wright, states that he found the maximum effect of calcium was pro- 


