ACETIC ACID 



The processes employed for the manufacture of Acetic Acid, which is principally 

 used in the arts, and those for the production of Vinegar, which is chiefly for domestic 

 use, are widely different and carried on in separate works ; they will, therefore, be best 

 described under their respective heads. 



MANUFA.CTUBE OF ACETIC ACID (PYBOLIGNEOTJS ACID). 

 A. By destructive distillation of Wood. 



The general nature of the process of destructive distillation will be found detailed 

 under the head of DISTILLATION, DESTRUCTIVE ; as well as a list of products of the 

 rearrangement of the molecules of organic bodies under the influence of heat in closed 

 vessels. We shall, therefore, at once proceed to the details of the process as specially 

 applied in the manufacture of acetic acid from wood. 



The forms of apparatus very generally employed on the Continent for obtaining 

 at the same time crude acetic acid, charcoal, and tar, are those of Schwartz and 

 Eeichenbach ; but in France the process is carried out with special reference to the 

 production of acetic acid alone. 



The following is a description of that in use at Nuits and Kouen : 

 Into large cylindrical vessels (Jiff. 1) made of rivetted sheet iron, and having 

 at their top and side a small sheet-iron cylinder, the wood intended for making 

 charcoal is introduced. To the upper part of this vessel a cover of sheet iron, 'B, is 

 adapted, which is fixed with bolts. This vessel, thus closed, represents, as we see, 

 a vast retort. When it is prepared, as we have said, it is lifted by means of a swing 

 crane, c, and placed in a furnace, D (fig. 2), of a form 

 relative to that of the vessel, and the opening of the 

 furnace is covered with a dome, E, made of masonry 

 or brickwork. The whole being thus arranged, heat 

 is applied in the furnace at the bottom. The moisture 

 of the wood is first dissipated, but by degrees the 

 liquor ceases to be transparent, and becomes sooty. 

 An adapter tube, A, is then fitted to the lateral cylinder. 

 This adapter enters into another tube at the same 

 degree of inclination, which commences the condensing 

 apparatus. The means of condensation" vary according 



to the localities. In certain works they cool by means of air, by making the 

 vapour pass through a long series of cylinders, or sometimes, even, through a 

 series of casks connected together ; but most usually water is used for condensing, 

 when it can be easily procured in abundance. The most simple apparatus employed 

 for this purpose consists of two cylinders, F F (fig. 2), the one within the other, 

 and which leave between them a sufficient space to allow a considerable body of 

 water to circulate along and cool the vapours. This double cylinder is adapted to 

 the distilling vessel, and placed at a certain inclination. To the first double tube, 

 F F, a second, and sometimes a third, entirely similar, are connected, which, to save 

 space, return upon themselves in a zigzag fashion. The water is set in circulation by 

 an ingenious means now adopted in many different manufactories. From the lower 

 extremity, G, of the system of condensers, a perpendicular tube rises, whose length 

 should be a little more than the most elevated point of the system. The water, 

 furnished by a reservoir L, enters by means of the perpendicular tube through the 

 lower part of the system, and fills the whole space between the double cylinders. 

 When the apparatus is in action, the vapours, as they condense, raise the temperature 



