Brown.—Studies in the Physiology of Parasitism. I. 341 
The amount of agreement obtained in experiments of this sort may be 
judged from comparison of the results of the two experiments tabulated 
above. A similar investigation with respect to KC 1 gave retarding effects 
somewhat less than those of KN 0 3 . 
A detailed investigation of a variety of salts was not attempted. 
A certain number were, however, tested in this respect in order to see 
if the effects were in any way general; and in particular a salt of calcium 
was included in the list with a view to determining if it exerts any special 
action upon the extract, seeing that calcium is known to be a constituent of 
the middle lamella. The figures are given in the table below. In the case 
of each salt solution employed, it was previously ascertained that it showed 
a neutral reaction (this precaution must be particularly exercised with 
solutions of calcium chloride, which are liable to contain free alkali). 
Time for Standard Extract = 17-20'. 
Salt. 
m 
m 
2 and ™ 
64 
16 
4 2 
NaCl 
60 
165 
X 
KC 1 
20 + 
70 
X 
NH 4 C 1 
20 + 
135 
X 
Na-Ac 
70 
90 
X 
K 2 Ox 
50 
X 
X 
Na 2 S 0 4 
40 
90 
X 
K 2 S 0 4 
70 
115 
X 
MgS 0 4 
X 
X 
X 
CaCl 2 
50 
X 
X 
x Coherent after 3 hours ; devoid of coherence after 20 hours. 
A subsidiary experiment with the last three salts showed that in 
no case were the retarding effects due to alteration of the tissue by the salts 
employed. 
As expected, different salts show marked variation in their retarding 
actions. It is not proposed to draw any general conclusions from the above 
figures, as it has not been thought fit for the present to pursue this subject 
intensively. It appears, however, that no special action is to be ascribed to 
the calcium salt in this connexion. Also, the strong retarding effect of the 
magnesium sulphate is noteworthy. 
Of other crystalloidal neutral substances , only two have been investi¬ 
gated—saccharose and glucose. No definite retarding effect has been 
demonstrated in the case of these. 
Time for Original Extract — 30'. 
m 
m 
m 
m 
64 
16 
4 
KNOg 
55 
150 
10 hrs. 
Saccharose 
30 
30 
30-35 
30-35 
Glucose 
30 
30 
30-35 
30-35 
