Miscellaneous Results from the Laboratory. 617 



process this latter product is heated in a furnace with powdered chalk and 

 coal, in which operation the sulphate of soda is changed into a mixture of 

 carbonate and caustic alkali. "When removed from the furnace the mix- 

 ture is treated with water to wash out the soda. An insoluble residue now 

 remains, containing lime and sulphur in astate of combination, which it is 

 unnecessary to explain in the present place. It should be observed, how- 

 ever, that this alkali waste luhen fresh possesses caustic properties which are 

 believed to be highly dangerous to vegetation. After a time, by exposure 

 to the air, the whole sulphur compounds become converted into sulphate 

 of lime, or gypsum ; and the refuse can then be employed without the 

 smallest fear to any variety of produce. 



A gentleman in Wales, living near to some alkali-works, had the oppor- 

 tunity of purchasing a quantity of this refuse, which accumulates largely 

 in the works, much to the annoyance of the alkali manufacturers. A spe- 

 cimen was sent to the laboratory, and analyzed by Mr. Ogston, with the 

 following results : — 



Analysis of Alkali Waste. 

 Carbonate of Lime . . . . . 30*60 



Sulphate of Lime 60-17 



Water 2-13 



Sand, &c 3-28 



Oxide of Iron, Alumina, and loss in ) r, n.-, 

 analysis j 



100-00 



It might reasonably be imagined that some portion of soda would 

 remain in the mass — such, however, was not the case ; the manufacturers 

 taking especial care to lose none of their important products. Nor, if 

 it had been so, would it much have affected the value of the waste as 

 manure. 



Essentially, then, alkali-waste consists of sulphate and carbonate of lime, 

 and may be used with advantage and economy wherever gypsum would be 

 of use. 



The above was purchased at the rate of Is. per ton. 



'Woollen Refuse.— W ooWqw rags are well known to farmers as a powerful 

 manure. Owing to their slow decomposition they ar;^ not well fitted for 

 root-culture ; turnips, and other plants of this kind, requiring active and 

 readily-soluble manures to produce a rapid growth. 



To wheat and to hops woollen rags are applied with the best effects. For- 

 merly they were to be purchased of good quality and unmixed with any 

 less valuable substance; but of late years rags of a size that used to be 

 sold to the farmers are bought up to be re-converted into an inferior 

 kind of cloth. The supply, being thus in part cut off, is frequently made 

 good by the admixture of such linen or cotton rags as may not be worth 

 the paper-maker's attention. The composition of wool in a state of purity 

 was some years ago ascertained: it contains upwards of 17 per cent, of 

 nitrogen. Were woollen rags, therefore, of the same strength as the wool 

 itself, they should produce ultimately a larger amount of ammonia than 

 even pure Peruvian guano. 



To reason from the composition of a raw material of any kind upon that 

 of the manufactured article which has passed through perhaps half a dozen 

 different processes, is often to lay oneself open to much error ; and nothing 

 short of the direct analysis of the rags themselves would enable any person 

 to form a correct notion of their manuring value. 



A short time since the Earl of Tyrconnel suggested to me the desirable- 

 ness of analyzing specimens of wool refuse, very justly remarking that, if 



