184 
REVIEW. 
compared with those obtained from the application of soft and pure water. 
‘ Wlien water is liard,’ she remarks in her Usotefi on Nursing, ^ it is worth 
while to have distilled water for every water-dressing,’ Tliere can be no 
doubt that water charged with mineral and organic impurities must exert a 
very deleterious influence on wounds already but too predisposed to un¬ 
healthy action. Tor this and all other external applications to the body, 
especially in sickness, water purified and oxygenated by means of the per¬ 
manganates will be found extremely valuable.” 
Adverting to the purification of air, Mr. Condy remarks 
that— 
“Air is the chief necessary of life, and respiration the first and last act 
of onr existence as independent beings. The necessity for due supplies 
of food, however imperative, is one that admits of modification; life, and 
to a certain extent health, are not incompatible with an occasionally scanty 
and irregular allowance of nourishment. But the essential conditions of 
respiration are that it shall be never-ceasing and unrestrained. Each inspi¬ 
ration exerts its influence instantaneously, and with the expiration which 
follows, its action terminates. The air we breathe surrounds us acef rdingly 
on all sides, in inexhaustible quantities, and is drawn upon by every human 
being, without thought or eftbrt, at the rate of from fifteen to twenty re¬ 
spirations ]}er minute. Uidike food, which, in order to be able to support 
the numerous tissues of the body, must be su))plied of various kinds, air, to 
be fitted for its assigned duty, demands no precaution beyond that of 
guarding against contaminalions of foreign matter; for in all situations on 
the globe, and at every elevation within our reach, the free mass of the 
atmosphere maintains a uniform composition, so far as its essential elements 
are concerned.” 
Having given the constituents of the atmosphere, our 
author goes on to observe that, besides these,— 
“The atmospherecontains minute portions of all substances susceptible of 
remaining aeriform at ordinary degrees of heat and pressure, as well as of 
every n alter, whether solid or fluid, which is capable of being dissolved or 
suspended in the atmospheric mixture. These may be regarded rather as 
accidental than normal constituents. It is they which for the most part 
constitute the contaminations of the atmosphere. IVith few exceptions, 
they are substances of an oxidizable nature. Tliey consist of a great 
variety of moie or less diffusible products, such as the gases generated by 
combustion and similar ))rocesses ; traces of nitric, acetic, and sulphurous 
(or rather sulphuric) acids, of nitrate, acetate, and hydrosulphate of am¬ 
monia, and, in certain maritime situations, of muriatic acid and iodine; 
exhalations from the organic kingdoms, morbid emanations I’rom men, 
animals, and plants, when suffering from disease, and the results of their 
decomposition after death; as well as of numerous forms of more or less 
tangible solid substances, such as carbonaceous matter, infusoria and other 
microscopic organisms, pollen of plants, spores and germs of some low 
orders of living beings, and finely subdivided inorganic matter. As even 
the litter group of bodies are invisible to the naked eye in ordinary ditfused 
light, none of the above substances can be regarded as cognizable to the 
senses except when they nalurally possess or liappeu to acquire odorous 
properties. They ihen become jiereejitibly offensive, and cause the atmo¬ 
sphere in which they exist to be disiinguislu d as ‘ bad ’ or ‘ foul.’ It is 
])riiicipally tl;e truly gas* ous class of impurities which are ])ossessed of 
smelling projierlies, although, on the one hand, some of them, and those 
not the least deleterious, such as carbonic oxide, are devoid of odour; and 
