

IMPORTANT NEW EXPERIMENTS 131 
me to be a fluid specially favourable for use in 
attempting to throw light upon this problem :— 
first, because of the unanimity of experimenters as 
to the fact that, when boiled in its acid state and 
subsequently guarded, it invariably remained barren ; 
and secondly, because the marked acidity of urine 
would necessitate the use of liquor potassz in easily 
measurable quantities, even when providing for the 
neutralisation of such small portions of fluid as 
are commonly employed in these experiments. 
The unanimity of previous investigators as. to 
the barrenness of urine after it has been boiled 
in its acid state and subsequently protected from 
contamination, is remarkable, as may be seen from 
the following quotations. 
M. Pasteur, speaking of sweetened yeast-water and 
of urine, says!:—‘‘ Nous avons reconnu que ces 
liquides, portés a la température de l’ébullition a 100° 
pendant deux ou trois minutes, puis exposés au con- 
tact de lair qui a subi la température rouge n’éprou- 
vent aucune altération.” The latter of these fluids 
may remain, he says, indefinitely, “sans éprouver 
d’autre altération qu’une oxydation lente de la 
mati¢ére albumineuse,” and this even ‘a la tempéra- 
iwe de 25 4 30°, température si favorable a. la 
putréfaction de urine.” 
Professor Lister? calls forcible attention to ex- 
periments with boiled urine in support of the germ 
theory—its continued barrenness, when protected 
1 Ann. de Chimie et de Phys., 1862, t. lxiv., pp. 58 et 52. 
2 Introductory Lecture, delivered in the University of Edinburgh, 
1869, p. 19. 
