-conductors.

Silk ranks next to wool in warmth and porosity. It is much softer and
less irritating than flannel or merino, and is very useful for summer
wear. The practical objection to its general use is the expense. Fur
ranks with wool as a bad conductor of heat. It does not, however, like
wool, allow of free evaporation. Its use in cold countries is universal,
but in milder climates it is not much worn.

Cotton and linen are good conductors of heat, but are not
absorbents of moisture, and should not be worn next the skin. They are,
however, very durable and easily cleansed. As an intermediate clothing
they may be worn at all seasons, especially over wool or silk. Waterproof
clothing is also useful as a protection, but should not be worn a longer
time than necessary, as it shuts in the perspiration, and causes a sense
of great heat and discomfort.

The color of clothing is of some importance, especially if exposed
directly to the sun's rays. The best reflectors, such as white and light
gray clothing, absorb comparatively little heat and are the coolest, while
black or dark-colored materials, being poor reflectors and good
absorbents, become very warm.

251. Suggestions for the Use of Clothing. Prudence and good sense
should guide us in the spring, in changing winter flannels or clothing for
fabrics of lighter weight. With the fickle climate in most sections of
this country, there are great risks of severe colds, pneumonia, and other
pulmonary diseases from carelessness or neglect in this matter. A change
from heavy to lighter clothing should be made first in the outer garments,
the underclothing being changed very cautiously.

The two essentials of healthful clothing are cleanliness and
dryness. To wear garments that are daily being soiled by perspiration
and other cutaneous excretions, is a most uncleanly and unhealthful
practice. Clothing, especially woolen underclothing, should be frequently
changed. One of the objections to the use of this clothing is that it does
not show soiling to the same extent as do cotton and linen.

Infectious and contagious diseases may be conveyed by the clothing. Hence,
special care must be taken that all clothing in contact with sick people
is burned or properly disinfected. Children especially are susceptible to
scarlet fever, diphtheria, and measles, and the greatest care must be
exercised to prevent their exposure to infection through the clothing.

We should never sleep in