( 53) 
VIL—WMiscellaneous Observations on Blood and Milk. By Joun Davy, M_D., 
F.R.S., Lond. and Edin., Inspector-General of Army Hospitals, L. R 
(Read April 7. 1845.) 
1. On the State of Combination of the Alkali in the Blood. 
The condition of the alkali in the blood—of that portion on which its alkaline 
reaction depends—has been the subject of much speculation, and of many experi- 
ments. ENDERLING is one of the latest inquirers who has given it his attention. 
After having made an analysis of the ashes of the blood, he has come to the con- 
clusion, that the alkali in it is in combination with phosphoric acid, the former 
predominating in the form of the tribasic phosphate of soda.* 
Granting the accuracy of EnpERLING’s analytical results on the ashes, does it 
follow that his inference must be correct relative to the condition of the alkali in 
the liquid blood? It appeared to me doubtful @ priori ; and the doubt I enter- 
tained was confirmed by experiment. The doubt arose from considering the ten- 
dency of the alkaline carbonates, when strongly heated with charcoal, to be 
reduced ; and when heated with phosphate of lime in excess, to exchange their 
carbonic acid for a portion of the phosphoric—the acid gas of course escaping, 
and compounds of lime and alkali remaining, each with excess of base. In accord- 
ance with this, when I have added carbonated alkali to the coal obtained from 
blood, and have reduced the coal to ashes, I have not been able to detect in the 
lixivium obtained from them any trace of carbonic acid. Moreover, I find that 
the carbonate of soda is liable to loss when heated strongly, exposed to the air; 
and, consequently, when it exists in a small quantity in a bulky coal, the whole 
of it may be dissipated—carried over much in the same manner as boracic acid is 
in combination with water as a hydrate, when it is subjected to heat. 
If ENDERLING’S view were correct, the blood, after having been acted on by 
the air-pump, ought not in its fresh state to yield any carbonic acid on the addi- 
tion of an acid. This is the experiment alluded to, which confirmed my doubt. 
I find that blood or its serum, after having been so acted on until perfectly tran- 
quil, has effervesced strongly, when mixed either with dilute sulphuric or muriatic 
acid purged of air, or with a solution of cream of tartar. And, in accordance with 
this, I have also found that serum, after having been subjected to the air-pump, 
gives on coagulation, by immersion in boiling water, a different result, whether 
* See Mr Pacet’s Report on the Progress of Human Anatomy and Physiology, in the British 
and Foreign Medical Review for January 1845, 
VOL. XVI. PART I. O 
