406 ON THE UTILIZATION OP WASTE. 



within the last few years we have learned actually to take up and apply 

 the bones of extinct animals — of the old reptiles which, during the 

 Saurian period, spread terror through the seas and estuaries of the time. 

 The bones and exuviae of these animals are now used as manure. They 

 are ground and mixed with sulphuric acid, and sold under the name of 

 " superphosphate of lime." 



In this country the importation of bones for mechanical and 

 chemical purposes, amounts to about 70,000 tons per annum. The 

 mechanical purpose for which bones are used are such as the making 

 of handles for knives, tooth, and nail-brushes, &c. The quantity im- - 

 ported represents a money value of 350,000Z. 



When we examine the chemical composition of bone, we find it to 

 consist of organic matter 33 parts, of phosphate of lime 56 parts, of 

 carbonate of lime 8 parts, and of fluoride of calcium and phosphate of 

 magnesia 2 parts, making 100 parts. Now, I can easily show you the 

 earthy matter, taking it generally, and the organic matter. I have 

 here put a bone, which was of the form you see it here, in a little 

 weak muriatic acid. That has dissolved out the earthy portion and 

 left the organic matter of the cartilage, which you see is cpiite 

 soft. Now, this cartilage is extensively used for purposes which I have 

 not time to enter into, because that is not what I have to deal with. 

 It is used extensively in making a glue or size used for stiffening calico 

 prints, which is of a less stiff and firm character than the glue used for 

 ordinary purposes. The bones are boiled, and this cartilage becomes 

 converted into gelatine, or into the jelly with which you are familiar 

 under the name of " calve's-foot jelly," in which the cartilage is 

 changed into a gelatinous substance. This is extensively used, and 

 it is a subject which one would like to dwell upon. 



Bone Black. — If instead of taking out this gelatine by boiling it, 

 you take the bones and calcine them with this cartilage in them, the 

 bones are converted into a black substance which is called " bone-black." 

 The fact is, the cartilage becomes carbonised, the volatile matters are 

 driven off, and the earthy matters of the bone become mixed with char- 

 coal, which remains behind. This charcoal is extensively used for the 

 purpose of decolourisation. It is that which is employed for the pur- 

 pose of making brown sugar white. If any coloured organic substance 

 be passed through these calcined bones, and you allow it to go gradually 

 you will find that it filters through with the colour, perhaps not wholly 

 removed by the first operation, but it will be removed by the second. 

 You see this liquid is now passing through almost wholly decolourised, 

 because this charcoal has a strong affinity for the colouring matter and 

 unites with it. Bone-black is extensively used for decolourising syrups 

 and other things. When this bone-black is formed by the calcination 

 of the bones, there is also a large quantity of oil which distils over, and 

 is sold under the name of "Dipper's animal oil," being useful for 

 various purposes. 



