[NICHOLLS] CALCIUM CONTENT OF THE BLOOD 93 
duced in an hour or less. The difference of 2 points is not greater than 
the possible error in observation. Further, the pulse rate which at first 
was sixty-eight was the sixty-eight at the end of the experiment. The 
only effect produced was slight nausea and fulness in the head for a few 
moments, and a speedy action of the bowel. The motion was not 
watery but well formed and preceded by slight cramp so that I judge 
the action of the calcium was upon the intestinal muscle rather than on 
the secreting structure. So far as I could see, therefore, the effect of 
this large dose, a dose greatly in excess of the daily amount usually 
given therapeutically, was nil so far as the circulation was concerned. 
Clinically, I have found no constant relationship between the calcium 
index in the blood and the blood pressure. Thus in typhoid fever, in 
one case with a blood pressure of 112, the calcium index was 0.802; with 
a blood pressure of 111 the index was 0.8. In the same case at other 
times, with a blood pressure of 102 the index was 0.708; and with a 
pressure 107 the index was 0.58. Again in case of pneumonia with a 
blood pressure of 140 the index was only 0.132. 
The bearing of the calcium content of the blood on the coagulation 
time is also open to debate. Using the Wright coagulometer, in a case 
of pneumonia, in which disease the blood is supposed to contain a large 
amount of the fibrin-forming elements, the coagulation time was four 
minutes and a quarter (the normal time being two or three minutes) 
with a very low calcium index. To cite only one other instance, in a 
case of typhoid the coagulation time was found to be at one time four 
and a half minutes; at another, two and three-quarter minutes, with 
a calcium index practically the same in both cases. 
We owe the prevalent belief that the administration of calcium 
salts will increase the fibrin forming power of the blood so as to shorten 
its coagulation period, while salts of citric acid have the opposite effect, 
mainly to the influence of Sir A. E. Wright, who, since his first publi- 
cations! in 1893, has brought out a number of papers containing experi- 
mental evidence in favour of this position. Subsequently much clinical 
evidence has been accumulated to show that the exhibition of calcium 
salts is a valuable therapeutic resource in diseases characterized by im- 
perfect coagulating power of the blood or a tendency to serious transu- 
dation. Wright’s results showed that a dose of thirty grains of calcium 
chloride would reduce the coagulation time from a quarter to a half of 
the time required when the drug had not been given. It is only lately 
that Wright’s results have been seriously questioned. The chief icono- 
clastic work has been done by Addis who in two recent papers’ gives the 


‘Sir A. E. Wright, Journal of Pathology and Bacteriology, 1; 1892; 434: also 
British Med. Jour., 2; 1893; 223. 
2 Addis. The Quarterly Journal of Medicine, 2; 1909; 149, and British Medica 
Journal, 1; 1909; 997. 
