

EXPERIMENTS WITH SALINE SOLUTIONS 233 
acids, and attention was finally concentrated upon a 
few solutions, the exact composition of which will 
be presently detailed. Some experiments have also 
been made with sea-water, as one of the most 
probable sources of the primordial living things 
which first appeared on this earth. Though not as 
free from germs as the saline solutions in distilled 
water, certainly sea-water is not a medium likely to 
contain desiccated Bacterial germs, and therefore 
the mere boiling of such a fluid ought to 
prove destructive of all living things con- 
tained therein. 
The fluids with which experiments were 
made were contained in sterilised tubes, / 
mostly of soft German glass, three inches | 
long and one inch or rather less in diameter, | 
and provided with a tapering extremity. 
The glass from which the tubes were to 
be blown was first well cleaned, and, natur- 
ally, during the process of making the tubes 
they became thoroughly sterilised. The 
advantage of this condition was maintained 
by the fact that the tubes weré sealed as they 
were made, and that they, in all cases, re- 




: . Fic. 12. 
mained closed until they were about to be = ¢.ujeq 
charged with experimental fluids. When Tube after 
half-filled each tube was carefully sealed ae 
again in the flame of a Bunsen’s burner, deposit of 
thus presenting the appearance shown in “<- 
Fig. 12. The meaning of the deposit at the bottom 
will be subsequently explained. 
The closed tubes were immersed in a can of water 
