50 ANNUAL OF SCIENTIFIC DISCOVERY. 



proposition as the most deserving of notice. As much muriate of ammo- 

 nia is added to the water as it contains carbonate of lime in solution. This 

 agent also softens old incrustations, but for this purpose something more 

 than the quantity just mentioned is required. Its action is chemical ; 

 from the muriate of ammonia and sulphate or carbonate of lime, are 

 formed chloride of calcium and sulphate or carbonate of ammonia. The 

 latter salt is somewhat volatile ; if the steam is to be employed in heating 

 color baths, it is necessary to ascertain whether the volatile alkali will have 

 an injurious action. Eisner states that one pound of muriate of ammonia 

 is sufficient for twenty cubic feet of well-water containing gypsum. 

 Muriate of ammonia is preferable to carbonate of ammonia. In the 

 Verhandlungen des Hollandischen Ingenieurferei/ts, there are two papers on 

 the employment of muriate of ammonia. The first, by A. A. C. de 

 Vries-Robbe, shows, that in the locomotives on the Dutch railways two 

 ounces of muriate of ammonia for each boiler is sufficient to clean incrust- 

 ed boilers in a few days. This quantity, put in twice a week, keeps the 

 boiler quite clean ; iron and copper are not dissolved by it. The second 

 paper, by C. Schefter, states that in the royal wood-cutting establishment 

 of Holland, a perfectly clean boiler was supplied weekly for four months 

 with two-tenths of a pound of muriate of ammonia, when forty potinds 

 of scale were found to have been deposited. The boiler was worked four- 

 teen hours daily, with water containing gypsum. 



"With the addition of four-tenths of a pound of muriate of ammonia 

 twice a week for five months, with the same amount of daily work and the 

 same water, sixty pounds of scale had deposited. In both cases, the de- 

 posit was more upon the sides than upon the bottom of the boiler, and 

 much less than without the use of sal ammoniac. 



Mixture of Extract of Tannin. J. Delfosse patented a mixture of 

 twelve parts chloride of sodium, two and one-half parts caustic soda, one- 

 eighth extract of oak bark, one-half of potash, for the boilers of stationary 

 and locomotive engines. The principal agent in this appeal's to be the 

 tannin of the extract of oak bark. Eisner recommends the roughly cut 

 root of the common tormentil for this purpose, on account of the large 

 quantity of tannic acid it contains. 



A patented process is now in use in England, which must be mentiored 

 here. Spent tanner's bark is put into the boiler. To avoid the chance of 

 the bad result already referred to with* the sawdust, the bark is put into a 

 perforated vessel, which is suspended near the surface of the water, and 

 kept in the right position by means of a float. The bark is renewed from 

 time to time. The patentee supplies the whole apparatus for about 2 

 105, and publishes many testimonials to show that his process is perfectly 

 successful. 



According to Cave, pieces of oak wood, suspended in the boiler and 

 renewed monthly, prevent all deposit even from waters containing a large 

 quantity lime. The action must depend principally upon the tannic 

 acid. 



