FABRICATION OF WINE-VINEGAR. 189 



of 3f inches apart, and 5f inches in larger vats, holes, I, Fig. 42, 

 of 0.39 inch diameter are then bored in the wall of the vat ; one 

 hole is, however, bored in a place about 0.39 inch deeper than /, 

 and in this hole is fitted a glass tube, g, bent at a right angle, 



Fig. 42. 



Vat for the Preparation of Wine- Vinegar. 



under which is placed an ordinary tumbler. In the bottom of 

 the vat is a tap-hole, Z, closed by a stopper. 



If the vat be filled during the operation with wine, the latter 

 can only rise until it begins to run off at g. The level of the fluid 

 being but little below the holes /, an uninterrupted change in the 

 layer of air above the fluid takes place. A wooden spigot, H, is 

 fitted in the vat about f to 1 inch above the bottom. In the 

 centre of the lid D, which lies loosely upon the vat, is an aper- 

 ture, 0; in a second aperture a thermometer, T, is inserted, 

 whose bulb dips into the fluid ; and in a third aperture is fitted a 

 glass funnel, R, reaching nearly to the bottom of the vat. 



The operation in such a factory commences with the cultivation 

 of the vinegar ferment. For this purpose as many shallow por- 

 celain plates as there are vats are placed upon the table and wine 

 to the depth of | to j inch poured in each ; the room should be 

 heated and kept at a temperature of 86 F. The manner of the 

 development of the vinegar ferment upon the fluid in the plates 

 as well as the precautions which have to be taken has already 

 been described. In the commencement of the fabrication the 

 cultivation of the ferment requires great attention, it being fre- 

 quently disturbed by the development of mold ferment, but 

 when the factory is once in a proper state of working it is readily 

 effected because the air of the workroom - then contains a large 



