256 
POPULAR SCIENCE REVIEW. 
The cotton-wads, with which engineers clean their machinery, are after- 
wards worked up into some descriptions of shoddy. Cotton-waste, “ the 
refuse cotton of the mills,” is another article of considerable importance, 
it being manufactured into writing and printing paper ; whilst in America 
it is made into an imitation of papier maclie. 
Oakum made from old ropes, again, is the product of a waste substance. 
Mr. Simmonds states that 1,400 tons, valued at £28,000, are sold annually 
in Liverpool. The total imports of codilla or tow (the waste fibres which 
occur in the cleansing of hemp and flax), amounted in 1857 to 13,000 tons, 
valued at £373,000. It is manufactured into bags, yarn, &c. 
Bones form another waste product, though no longer wasted, and Mr. 
Simmonds gives a very interesting account of the changes which they 
undergo. Bones are made into manure as superphosphate of lime, or 
turned into handles for knives, fans, tooth-brushes, umbrellas ; or con- 
verted into buttons, children’s rattles, &c. They are also largely used in 
the manufacture of animal charcoal (a very important agent in refining- 
sugar). Bones are boiled for the sake of the gelatine which they contain, 
and this gelatine is used by dyers, and not unfrequently by cooks ; the 
fatty matter obtained being made into soap. The value of bones imported 
and collected at home is calculated to amount to £700,000 per annum. 
This book contains one of the most interesting biographies, that of a 
dealer in refuse bread, bread crumbs, crusts, &c., which has ever come 
under our notice. 
We must glance rapidly over the list of waste substances, and refer our 
readers to the complete and varied information which Mr. Simmonds 
supplies on each subject. 
The saw-dust of various woods is a waste product of importance, and 
employed for a variety of purposes. The husk of the grape, after the fruit 
has been crushed, is used in making a weaker wine, and also in the manu- 
facture of vinegar. Oil-cakes, formed from seeds after the oil has been 
crushed from them, are of great commercial importance. 
We must not omit to mention another waste material — the waste paper 
of the Government offices, which sells annually for £7,000. 
Dead dogs in Paris and New York are no longer wasted, they are boiled 
down, and their fat used in the preparation of kid-gloves. Old horses form 
a perfect mine of wealth, and Mr. Simmonds gives a very curious list of 
the purposes to which their “remains ” are applied. 
The waste products of coal show perhaps the most extraordinary results 
of chemical researches. Gas-water, formerly allowed to run to waste, is now 
eagerly bought up. The residual products of coal are very numerous, and 
amongst them are ammoniacal-water, employed in making sulphate and 
carbonate of ammonia, sal-ammoniac, and alum; coal-tar, which contains 
a variety of products ; naphtha, employed as a solvent, and for burning 
purposes ; benzol, the basis of the endless shades of mauve, Magenta, 
roseine, &c. Another product is paraffin- wax, which is made into candles; 
and another creosote, from which carbolic acid is obtained, largely used as 
an antiseptic. Carbolic, in combination with nitric, produces picric acid, 
from which are obtained the beautiful greens and yellows so much ii> 
fashion of late. 
