CHEMICAL SCIENCE. 217 



the latter it has the advantage of not destroying to so great an extent the 

 fibre of the pulp. 



Since the details of the process, \vhich for that matter consists merely of 

 arrangements f or thoroughly washing and cleansing the carbonic acid 

 employed, the latter being then introduced into the bleaching vats, just as 

 if it were steam, through coils of pipe pierced with holes, which are placed 

 at the bottom of the vats, cannot well be explained without a diagram, 

 we must refer the reader who may desire these to the original article, in 

 which the apparatus is figured. Sitti man's Journal, F. H. Storer. 



NEW METHOD OF OBTAINING CARBONIC ACID. 



M. M. Meschelguck and Lionnet have proposed to the French Academy a 

 new and economical mode of obtaining carbonic acid. It is known that the 

 temperature at which the carbonate of lime is decomposed when vapor of 

 water is passed over it, is lower in proportion as the amount of moisture 

 present is increased; in fact, it will even give off all its acid if heated to 

 212 in a current of the vapor. The proposed new method of procedure is 

 as follows : Strong earthen retorts, filled with limestone, are placed in a 

 reverberating furnace, and the temperature is raised as needed. The retorts 

 communicate, at the back, with vapor generators, by means of tubes fur- 

 nished with cocks. When the retorts are at a uniform red heat, the vapor is 

 admitted by opening the cocks, and quantities of carbonic acid gas are at 

 once generated and received into a gasometer. 



THE ECONO3IY OF GLUTEN. 



In our starch factories an enormous amount of gluten is annually wasted, 

 or but imperfectly saved. Walter Crum, the well-known industrial chemist 

 of Glasgow, has devised a means of utilizing this material in dyeing and 

 calico printing. It is well known that many colors, for example, cochineal 

 and archil, which may be readily fixed on wool and silk (animal fibres), 

 have so little affinity for cotton and vegetable fibres as to render the dyeing 

 of the latter with them very difficult or impossible. But a few years ago, a 

 process which is technically designated the animalization of cotton was intro- 

 duced, consisting in coating the cotton fibre with an animal substance. For 

 this purpose, albumen from eggs and blood has been hitherto employed. 

 Crum accomplishes the same object by the use of gluten, which is a vege- 

 table product of the same composition as albumen, but much cheaper than 

 the latter, especially when occurring as a refuse in the starch manufacture. 



FILTER FOR CORROSIVE LIQUIDS. 



Boettger, of Frankfort, employs for the filtration of corrosive liquids a 

 glass" funnel, the neck of which is loosely plugged with gun cotton. This 

 substance, properly prepared, has the proper fibrous, porous texture for an 

 efficient filter, and being a product of the action of the most corrosive 

 agent, viz., mixed sulphuric and nitric acids, is scarcely attacked, even in 

 the slightest degree, at medium temperatures, by any single agent or solvent, 

 so far as known, except acetic ether. It may be employed for filtering 

 strong nitric acid, fuming oil of vitriol, permanganate of potash, strong 

 caustic potash lye, and aqua-regia. Even chromic acid may be separated 

 from its mother liquors by this niter. Irs use in drying crystals which have 



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