86o 



THE POPULAR SCIENCE MONTHLY. 



by itself, or after the addition of gelatin or 

 other appropriate cultivating matter, con- 

 sumes oxygen from the dissolved air at low- 

 er temperatures, but does not consume any 

 after heating to 60° C. for three hours, may 

 be regarded as having contained living or- 

 ganisms, but not of a kind able to survive 

 exposures to that temperature ; and a wa- 

 ter which, by itself or after the addition of 

 gelatin or the like, continues to consume 

 oxygen from its contained air after the wa- 

 ter has been heated to GO" C, is to be re- 

 garded as containing spores or germs of or- 

 ganisms that can survive that temperature. 

 Whether the power of resisting a given 

 temperature affords any clew to the inno- 

 cence or malignity of an organism is a ques- 

 tion for future biologists, and must be de- 

 cided by separate observations on each 

 known species. 



Amianthus. — Amianthus is a mineral 

 consisting of a double silicate of hydrate 

 of lime and magnesia with a little oxide 

 of iron or alumina. It generally occurs in 

 the form of silky fibers, sometimes nacre- 

 ous and having a greasy feeling, qualities 

 that give it a kind of organic aspect. It is 

 incombustible and infusible. It appears to 

 burn in the fire, but when it is withdrawn 

 from the flames it immediately returns to 

 its natural condition without having under- 

 gone any alteration. This property seems 

 to have been known from very early times. 

 The ancients are said to have used it for 

 winding-sheets for the bodies they placed 

 upon the funeral-pyres, the cloths made of 

 it holding the ashes of the dead sepa- 

 rate from those of the fuel. Whether 

 this be so or not, the secret was lost, and 

 amianthus was, till quite recently, nothing 

 but a natural curiosity. The art is now 

 practiced of introducing amianthus into 

 woven goods and of making with it a con- 

 siderable number of incombustible objects, 

 such as gloves, garments, and safety-ropes. 

 It has also been introduced into paints and 

 protective coverings for wood. As it is a 

 poor conductor of heat, is not attacked by 

 acids, and docs not act on metals, it makes 

 a good envelope, and has been found ex- 

 cellently adapted to application at the joints 

 of 6team-pipes. The manufacture of ami- 

 anthus is carried ou by an English company 



formed by the amalgamation of three rival 

 Anglo-Italian companies, which has control 

 of the most important beds of asbestus 

 known, particularly of those in England, 

 Italy, Corsica, and Canada. The Italian 

 asbestus is most sought after, on account 

 of the length, fineness, softness, and flexi- 

 bility of its fibers. The fibers of the min- 

 eral of other countries are shorter, harsher, 

 and less easily separated, and, therefore, 

 inferior. The fibers, the mineral having 

 been passed through a rolling-mill, are 

 stirred in a bath of hot water till they be- 

 come very supple. The longer fibers are 

 then taken out, washed, and sorted into 

 packages of uniform length, to be spun 

 into threads and woven into cloths, for 

 garments of various kinds, or into cords. 

 The shorter fibers are beaten into a pow- 

 der, and then mixed with linseed-oil into 

 a pulp very like paper-pulp, to which India- 

 rubber is added to give elasticity ; and this 

 makes an excellent paint for protection 

 against heat, particularly suitable for ap- 

 plication to steam-conductors, boilers, joints, 

 furnishing of every kind, and wood. 



A River made a Nuisance. — The " Lan- 

 cet " records the failure of the system which 

 has been applied, with great expense, for 

 disposing of the sewage of London by turn- 

 ing it into the lower part of the Thames. 

 It declares it the greatest nuisance of Eng- 

 land, and charges it with having made the 

 Thames a cesspool throughout its tidal re- 

 gion. " Of the existence of a tremendous nui- 

 sance," it says, " and of the urgent danger to 

 which it exposes the metropolis, there is no 

 longer any room for doubt. Hard as the 

 Metropolitan Board of Works fought, they 

 were utterly crushed by the evidence brought 

 before the late Royal Commission, and by 

 the stinging words of the commissioners in 

 their reports. They have, indeed, practi- 

 cally admitted the whole case against them 

 by adopting a costly system of disinfection 

 which could only be justified by urgent 

 necessity. The disinfection, it is true, is a 

 sham, utterly useless, and a gigantic waste 

 of the money of the rate-payers ; but it is 

 none the less a confession of the existence 

 of a nuisance created by the board, and for 

 many years defended by them as a public 

 blessing." 



