A class of organic bodies, produced by the oxidation of the secondary alcohols. They are nearly related to the aldehydes, from which they may be considered as derived by the displacement of H in the CO 11 group by the alcohol radicals. Thus common ethyl aldehyde becomes CH3COthe formula of dimethyl ketone, or, as it is commonly called, acetone which is the lowest member oi the series. Again, isopropyl alcohol by oxidation, yields acetone by the withdrawal of two hydrogen atoms C3H80 or CH3CIICH3 + 0 = CHjCH, + HaO.

From the seeds of Cola acuminata, containing caffeine.

A product of the kaurie pine of New Zealand. There is a large deposit ot kaurie gum peat in the soil of the buried kauri forest in New Zealand, and a considerable industry is carried on in the extraction of the gum ard associated oils. A ton of the peat yields about 10 per cent, of gum and gives by distillation about 64J gallons of oil, from which motor spirit, a solvent oil, a turpentine substitute, and paint and varnish oils are extracted. The sp. gr. of kaurie is ro5 and the meltingpoint about from 182 degrees to 2320 C.; it is used in varnishmaking and the preparation of dental compounds.

Mineral magnesium sulphate found in the Stassfurt salt deposits.

A soft, w hite, earthy deposit of hydrated silica, being the siliceous skeletons of minute aquatic plants knoftn as diatoms, found in Germany, the United States, and many other parts of the world. It is generally associated with earthy impurities, and contains from 65 to 87 per cent. Si02, 23 to 11*7 per cent. A1203, up to 3 per cent. Fe2<3, small proportions of the oxides of calcium, magnesium, potassium, and sodium, and from 5to 14 per cent, water. It id of great absorbent capacity, capable of taking up about four times its own weight of water and having a sp. gr. of about 033. It is largely used as an absorbent for carrying liquid petroleum, in the manufacture of dynamite, as a filtering material, iii ceramics, as an abrasive, cleanser, and polishing agent, and i>i compounding mixtures for boiler coverings, etc.

This assumes that gas pressure is due to bombardment of moving particles.

The ashes of burnt seaweeds, containing sodium carbonate, sulphate, and sulphide, together with the chlorides. of potassium and sodium, and insoluble substances comprising calcium carbonate, silica, and alumina. Kelp was at one time used for the extraction of both alkali and iodine, the latter being recovered from the motherliquor remaining after the crystallization of the salts from the extracted ashes. Two published analyses give the percentic parts as follows: Potassium sulphate…… Soi9o Soda as carbonate and sulphide 8555 Potassium and sodium chlorides 3653y5 The pressed coke is saturated successively with hot hydrochloric acid and water, and is afterwards used as a decolourizing agent. After removal of the sulphates from the brine liquor, it is heated in a vacuum pan to a certain point of concentration and then transferred to a vacuum crystallizer, in which the potassium chloride deposits. Upon further concentration the sodium chloride separates, whilst from the motherliquor iodine is obtained. In another process, the kelp is fed into one end of a rotary kiln, in which t encounters a flame of burning oil from the other end, thus producing a charcoallike mass which is subsequently quenched, ground and leached, or it may be burned to a grey loose ash with a potassium content equal to about 35 per cent. I20. About 8 lbs. iodine can be extracted from a ton of Scotch kelp.

Crystalline graphite deposited in iron furnaces from molten iron upon cooling.

A char made from charred sawdust purified by acid treatment, and admixed with animal carbon used for decolourizing.

A variety of pumice found in the Niijima Islands, used as a building material and for the construction of reinforced concrete barges, etc.