Some Misconceptions Concerning Asbestos.. 331 
have possessed asbestos napkins which they cleansed by 
means of fire, and that Charlemagne in like manner cleansed 
his tablecloth to the delight of his warrior guests. It is not 
improbable that these statements are to a large extent 
mythical; certainly, if true, the articles in question were 
not made of asbestos, the HYDRATED magnesian silicate. 
IV. The fourth misconception is that asbestos is pos- 
sessed of non-conducting qualities. This is perhaps the 
gravest and most widely spread of the several misconcep- 
tions and is held by many who should know better. As an 
example of the manner in which this last misconception is 
set forth, | may cite the following from an address of a 
well known geologist : “ Among the most important pro- 
perties of asbestos is that of non-conductivity or its power 
of resisting the action of heat.” Here we have the miscon- 
ception clearly stated ; it is that because asbestos is infus- 
ible it-must of necessity be a good non-conductor. The 
truth is that asbestos itself is a very poor non-conductor, as 
any one may prove by placing a vessel of water on a sheet 
of asbestos. cardboard and applying heat from below, or 
more simply still by placing a piece of wood or a sheet of 
asbestos millboard on a hot stove. If, however, asbestos is 
teased out and worked into a fluffy mass we then obtain a 
non-conducting material, but it is the air inclosed by the 
fibres that is the real non-conductor, the asbestos serving 
simply to entangle the air. The use of asbestos in the 
manufacture of non-conducting coverings for boilers, etc., 
is due to its fibrous texture and its infusibility. ‘The latter 
property gives it a decided advantage over hair and other 
fibrous materials which char under continued exposure to 
heat, while the exceeding flexibility of its fibres gives it a 
like decided advantage over mineral wool and other fibrous 
but brittle mineral substances. 
The removal of the misconceptions to which attention has 
been called, will in no respect tend to decrease the uses of 
asbestos, for the mineral has a sufficiency of good quality 
of its own to maintain and increase the demand; while, on 
the other hand, a true conception of its nature and proper- 
