THE UTILISATION OF WASTE GREASE FROM WOOL.

Otago Witness, Issue 1834, 14 January 1887, Page 8

THE UTILISATION OF WASTE GREASE FROM WOOL.

A NEW METHOD OF MAKING A CHEAP

AND USEFUL SOAP.

Everyone connected with the woollen trade is aware of the efforts that have from time to time been made to put to profitable use the waste products obtained from wool when it is being cleaused. The cleansing of wool is a costly and tedious operation, requiring the exercise of considerable caie and skill. More than half the waste removed from the wool in the process of purification consists of grease and nitrogen.' These products have frequently attracted the attention of chemists. Much wool contains far more grease than do many seeds and grains from which oily extracts are obtained. If this could be made into soap or into, a compound that could be used for washing wool, the nitrogen and sdme other constituents

of the remainder of the waste could be very^j profitably and advantageously disposed of : for use- as agricultuwl-manuj^.;*sh'ej^ttempt^tp. 1 make soap'of 'this" grease never^seemK to, have been thoroughly successful. Tne' article "produced lacked purity, and' gave off a disagreeable animal smell, which could not be got rid of by exposure to air and water ; but then if the' soap were used to cleanse wool and tissues,, it stained or otherwise injuriously affected .them. s In many cases the difficulty of dealing .'profitably with the grease nas proved to be so great that it is allowed to pass away with the refuse water into adjoining streams. The manufacture of potash from it has been'' carried on with more or less success in many parts ; but, owing to the discovery of potash deposits in Germany, its manufacture from wool grease is now frequently unremanerative. ■ • This subject is one which has attracted much attention in France, and effort/} have continually been made to utilise the waste for soap-making. At Elbceuf a manufactory was established for the purpose, but it was. recently given up as a failure. At Rbubaix some of 'the" wool-carders extraot potash from' the grease,* and then utilise the remainder for a soap, for their own use. Much trouble has been caused by the nuisance which has arisen from turning the greasy waste products into the rivers. At Rheims, La Veste, and other places, where the fall of thebedof the river is slight, and the flow sluggish, the grease has deposited in such large quantities that an oar may be pushed down into it to the level of the water, and it will stand perpendicular. In warm weather unhealthy and offensive gases rise in large quantities and poison the atmosphere of the whole neighbourhood. 'At Roubaix and Tourcoing the deposits in the "Espierre, which has its outlet in Belgium, have given rise to such serious and persistent complaints from the inhabitants of the district that the Belgian Government has threatened to dam the river up unless steps be taken to remove the nuisance. - Recently M. Rohart read a valuable paper before the French National Agricultural Society, in which he claimed to have discovered a method by which this wool grease can easily and cheaply be made into a soap that will be specially valuable for many purposes; When the grease is brought to its point of fusion, he finds that it will absorb certain mixtures of 'sulphur very readily, and to such an extent as' to retain in a fixed state 100 times its volume of sulphuretted hydrogen. After this operation, the sulphur, having becomej an integral part of the substance, it develops new properties which can be treated entirely differently from what the original grease could, and new results can be obtained. The grease becomes immediately and altogether soapy in a cold state. M. Rohart showed a piece of soap, as a sample of what is being regularly made and sold by Messrs Michaud Bros., of Aubervilliers. It possessed no odour of the original grease, nor of sulphuretted hydrogen. There is a very close combination between the principal constituents of the material. The mixture is fine and of perfect homogeneity. The article is not a toilet soap, and its origin indicates that it would not be very suitable for the skin ; but it is a cheap soap, and if what is said of it be true, should be very, useful and economical for many purposes.^ M. Rohart says' that the operation of making it is completed in less than an hour ; while the ordinary preparation of soap based on soda takes several days.' If there were placed, one above another, two troughs charged with this mixtare, a continual' manufacture of 50 tons of soap per day could be readily carried on, without appreciable, expense for fuel' and manual labour! l M. Rohart claims that this, chemical action is' new. unexpected, and of considerable interest ; and that, contrary to, previous knowledge and' experience, soap may now be completely made from fatty substances, of all kinds, not with caustic alkalies, but with carbonated alkalies, This he states to be a new scientific fact, aot confined to such fats as were formerly tran^ formed to acid fats, but a. general result, applicable to all substances of a soapy nature. That which is claimed to be new and certain is that in the presence of fatty substances, first suitably sulphuretted, the solutions of alkaline carbonates are immediately decomposed in a cold state. The carbonic acid liberates itself so abundantly that the mass rises and bursts out and overflows if the receptacle used be not deep enough. It is a case of atomical change, a simple phenomenon of substitution which reveals the force of the affinity of the alkalies of the 6ulphur. The carbonic acid is expelled from the combinations which it forms with the potash or the soda. The reduction of the cost of manufacture, especially in the matter of soda, is claimed to be considerable.

M. Rohart points out several ways in which this soap, with a large quantity of fixed sulphur in its composition, will be valuable. For the destruction of insects and parasites of all sorts on vines, vegetables, and agricultural crops of. various kinds, he considera that this soap may be more easily, pleasantly, and efficiently used than any of the powders, solutions, and vapours at present employed. For the purification! of infested linen, bedding, and clothing it is cheap, effective, and convenient, and has proved extremely satisfactory in the ' experiments that have been made with it in public lavatories and wash-houses, as well as in private Households. M. Roharts says that all his statements are based on actual experiment and fact, and not merely on theory. — Leeds Mercury.