On the Odors of Perfumes. 427 
the uses of rural economy. The use of coal tar has also been advised for 
the dead on the battle field. 
umas added that having often sought an explanation of these facts 
this case the odorous mixtures would be pate soe bee burned by the ozon- 
ized oxygen and the putrid odor rapidly destroye 
If coal tar really produces this action it is necessary, according to 
Dumas, to distinguish three effects. Ist, the penser - the infectious 
vapor or = by means of ozone arising ‘from coal tar. , the action of 
the plaster in preventing the production of new infections poh er by the 
solidification of the liquids present. 3d, the point of a t to the 
development of putrefactive process by any of the tons conta in 
coal tar, and especially the phenic acid which in the smallest traces in od 
form of wer of soda secures the preservation of animal matters 
- 
s of perfumes—On occasion of the discussion which we 
have ae Pie Mr. pease offered his ideas upon the mode of ac- 
tion of odoriferow 8 ‘substances, is discussion was mtended to recall the 
exert their oders when properly mixed with other odoriferous materials. 
Ist. Bodies dissiteabies odorant disguise the odors of other substances, 
as a strong light overpowers a feeble one. 2d. g them- 
selves odoriferous act in the manner of an acid in neutralizing a base. 
3d. Solid bodies may act by capillary affinity to absorb odors, as is the 
r example with charcoal. 4th. Other bodies act by es the 
constitution of the odorant substance, producing new compounds either 
odorless or nearly so. Such is the action of moist chlorine or oxygenated 
water. 5th. Lastly, the action may be two-fold, as in the case of — 
and ammonia, os page g one portion and neutralizing the other 
ut decompositio: 
Neutralization abies the largest class of cases; thus the volatile 
odorous acids are neutralized by alkalies to form odorless salts. Ammo- 
nia ieiandl its odor when united to an acid. The odors in sueh cases are 
truly neutralized, since displacing the acids liberates again the odors each 
in its own charac Examples of the destruction of odors are numeroys 
of odors, because at the same time we have decomposition of one part of 
the nee and the neutralization of another part by the chlorohydric acid 
MC hevreul proposes to define odors by means of a scale, analogous to 
our notation of sounds, or for gradations of color by the chromatic dia- 
gram (which last device we also owe to this savan. t). The great obstacle 
to this plan is the difficulty sudiione the sense of smell as we employ 
that of sight or hearing, a difficulty much increased by the toleration 
which the smell soon acquires to odors—becoming ‘ blase. 
