330 
but on the most scrupulous examination no organic forms 
could be discovered either in the tubes which had been kept 
at the ordinary temperature, or in those which had remained 
in the incubator. 
On August 11 the experiments were repeated under similar 
conditions, with the exception that the serum employed to 
fill the tubes was first rendered alkaline by the addition of 
0°5 per cent. of soda. In this case no organic forms had 
appeared in any of the tubes at the end of a month, nor 
could any be discovered afterwards. The superheated tubes 
were examined with the rest in March, 1871, with the same 
result. Two quantities of the same serum were kept in 
glasses side by side in the laboratory, to one of which only, 
soda had been added in the proportion already mentioned. 
In the one containing no soda a luxuriant growth of bacteria 
and leptothrix appeared in a few days, but nothing whatever 
could be found in the other. Soda, therefore, in the propor- 
tion of half per cent., appears to prevent the development of 
microzymes. 
II.— August 24, 1870.—The albumen of a fresh egg was 
collected in a clean dry test glass, and several tubes of 
tolerably large size were filled in the ordinary way and her- 
metically sealed. Some of them which were not heated 
were kept at the ordinary temperature, others were subjected 
in the hot-air oven to a temperature of 200°C. All of these 
tubes were kept until March, 1871, when it was found that 
the unheated tubes were still perfectly clear, with the excep- 
tion that on the side which was undermost as the tube lay 
on the shelf, its internal surface was lined with whitish 
granular deposit. The liquid showed no other change, and 
on a microscopical examination no organic forms could be 
found. The superheated tubes were in this respect in the 
same condition. From the negative results in the tubes 
which had not been heated, it might be inferred that white 
of egg is incapable of maintaining the life of microzymes, 
but we shall see hereafter that the fact admits of a totally 
different interpretation. 
IJI.—August 30.—A large number of capillary and other 
tubes were filled with a solution of sugar, tartrate of ammonia, 
and yeast ash, according to M. Pasteur’s formula, and divided 
into two batches, designated respectively a and 6. Some of 
the tubes @ after having been sealed, were kept either at the 
ordinary temperature or in the incubator. The rest were left 
masses of apparently semi-fluid material resembling oil drops. These masses 
are of a distinctly yellow colour, and vary indefinitely in size. They are 
found in superheated liquids immediately after they are prepared. 
