396 
Proceedings of Royal Society of Edinhurgh. [june 18 , 
The complementary minor of is the difference-product of 
{acd . . . , {ahd . . . 1 )^^^ , . • • ? (abe . . . , 
which by (/?) is equal to 
. . . h)Z\bcd. . . 1). 
Thus the alternant is equal to 
1 a Trfabc . . . h)^.A' 
In this identity put A' = {h cd . . . Z)”~ J . The left-hand side 
becomes the difference-product of 
(b e d , , , } {a c d , . , > • * • ? be,, . , 
which by {p) is equal to 
( - . 7r(a b c . . . h)^ ^-{a be ... 1) . 
Thus we have 
I a .. . 
{bed. , 
. . 0 ”’’ 
'r+l 
7 t(c d e . . 
■ l)r 
. be ... 1). 
4. Preliminary Note on a Method by means of which 
the Alkalinity of the Blood may quantitatively be 
Determined. By Professor John Berry Haycraft and 
Dr R. T. Williamson. 
It is a matter of some difficulty even to demonstrate that the 
blood is an alkaline fluid. The reason is that its red colour masks 
the reaction. The plasma itself is, however, practically colourless, 
and by allowing it to mingle with red litmus solution, after its 
corpuscles have been strained away, a blue tint may be observed. 
This was effected by Liebreich, who moistened dry neutral plates 
of plaster of Paris with litmus solution. Where this had dried he 
poured a drop of the blood that he wished to examine on to the 
plate. The plasma percolated with great readiness into the plate, 
but the red corpuscles, unable to do this, remained as a moist cake 
