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place from keeping the serum in India. Thus it will be noticed, on the one hand,
that while the serum which was seven months old and had been in India for only
three months (No. III) already showed a slight diminution in its neutralising power;
on the other hand, the sera which had been kept for some years in the Berars
(Hingoli and Ellichpur), i.e., No. VIII, and in Agra, i.e., No. VII, had practically
lost all neutralising power, and the sera which had been stored at Indore, Bombay,
and Nasik had deteriorated to a considerable extent, but had not completely lost
all neutralising power.

     Let us consider for a moment the climatic conditions as regards temperature
which prevail at these different places.

     In the cold season Agra and the Berars have a comparatively low temperature;
but for three or four months of the year the heat in these districts is excessive,
the maximum temperature in the shade being seldom below 105° F. and often
reaching 110° F. and over.

     Indore also has a severe hot weather and a comparatively cool cold season,
a similar climate in fact to that of Berar, although, perhaps, the maximum temperature
does not reach so high as in the other two cases.

     The greater neutralising power of the serum which had been kept at Indore
compared with the Berar and Agra samples, can be accounted for by the fact
that the former sample had been subjected to this great heat for only one hot
season, while the Berar and Agra sera had been stored in these districts during
two and four hot weathers, respectively.

     The results obtained with sera Nos. IV and V are especially interesting.
Both these sera were of the same age and were imported to Bombay at the same
time. One sample, viz., No. V, had been stored for a considerable time at Nasik
after Bombay. Now the temperature of Nasik during the cool season of the
year is much lower than that of Bombay. On the other hand, during the hot
months, March to May inclusive, the maximum shade temperature of Nasik is
only slightly lower than that of Bombay, while the minimum temperature is much
lower. On the whole, therefore, we may take it that the serum which had been
kept at Nasik had not been subjected to nearly such a high mean temperature
during the year as had that serum which had been stored in Bombay. In consequence,
the neutralising power of the former was more than a half greater than the
neutralising power of the latter.*

     We may conclude then from these data that anti-venomous serum undergoes
a progressive and fairly rapid deterioration when stored in hot climates, and
that this deterioration is greater and more rapid the higher the mean temperature
to which it is subjected.

     * Experiments are at present in progress in this Laboratory to ascertain, if possible, the causes of this
difference,— such as the effect of heating on the poison as regards the amount of serum required to neutralise
a given quantity before and after heating, etc.