4
show unmistakeable signs on the 9th morning. Stimson, however, was probably-
working with dried cord emulsions which may have introduced other factors.
His conclusion we accept in default of a better : " the reaction would therefore
seem to be caused by the foreign proteid of the rabbit nervous tissue itself and (is)
an expression of hypersensibility established by the early injections."
SECTION II.
HÆMOLYTIC DATA.
I. Some Factors which influence the Lysis of Erythrocytes by
Hypotonicity.
(I). During the course of endeavours to define the physical conditions which
t
end to promote and
to inhibit hæmolysis by a specific serum it was noticed that
the range of lysis of RBCs of different species of animals seemed to occupy distinct
spaces on the scale of NaCl solutions of varying degrees of concentration. To
ascertain whether any relation exists between the resistance of RBCs to hypotonic
l
ysis and their resistance to lysis by serums a number of observations was made
o
n
the RBCs of eight species with the view of arranging them in order of
resistances.
Method.— Blood from the animal was received into a solution containing
NaCl 0.85 per cent. and sodium citrate 1.0 per cent. The mixture was centri-
fugated and the RBCs were washed twice in 0.85 per cent. NaCl. A series
of tubes was prepared containing descending percentages of NaC1, each tube
differing from its adjacent ones by 0 .017 per cent. NaC1 and containing a total
volume of 2.45 cc. of fluid. Into each tube was dropped by a calibrated pipette
0 . 05 cc. of washed RBCs. After shaking once or twice, the tubes were put away
in the ice chest and the results read off next morning. The " lytic points " of the
RBCs under test, that is, the point of " complete lysis " and the point of the
" first trace " of lysis which could be plainly detected by the eye, were noted in
percentages of NaC1. RBCs from eight species and from twenty individuals
of each species were thus tested and the figures obtained are recorded in the
following table (No. 3) in percentages of NaCl. An inspection of chart No.
which was constructed from these figures makes clear in a moment the position
occupied on the salt scale by -the RBCs of each of the species tested :-
TABLE No. 3.
—
Man. Sheep. Goat. Horse. Rabbit. Dog. Guinea
pig.
Hen.
Mean of " Trace " points ...
...
...
.483
.740
.787
.606
.579
.500
.526
.442
Mean of " Complete" points
...
. . .
.353
. 6 0 1
.626
.448
.449
.364
.380
.288
Range of means
...
...
...
.. .130
.139
.161
.158
.130
.136
.146
.154
Highest " Trace " point ...
...
...
. 527
.850
.850
.696
.680
.544
.578
.476
Lowest " Trace " point ...
...
...
.442
.714
.714
.561
.527
.422
.476
.408
Range
...
...
...
..
...
.085
.136
.136
. 135
153
. 102
. 1 0 2
.068
Highest" Complete " point
...
. . .
.425
.731
.748
.493
.540
.408
.425
.323
Lowest " Complete " point
...
...
.323
.510
.544
.408
.357
.272
.340
.255
Range
...
...
...
...
..
.102
.221
.204
.085
.183
.136
.085
.068
It is observed that the mean range of lysis is very nearly the same in each
case, the average of the eight being equivalent to 0.144 per cent. NaC1, and that
the position of any particular species of RBC on the scale appears to be immaterial
as far as the range of its lytic points is concerned. In other words the majority of
the RBCs of any species are lysed at or about a particular dilution. of salt, and com-
paratively few are either much more or much less resistant than the majority.