INDIANA CANE GROWERS. 481 



vent fermentation, and since it enables us to use lime with less damage. For if 

 lime is put in first, and we get an excess, the excess will unite with the sucrose,, 

 and prevent crystallization. But if the bleacher is put in first, the excess of lime 

 will be absorbed by the excess of sulphur, and you get a light-colored syrup. 



It will not be out of place to conclude this paper by a few remarks on the man- 

 ufacture of bisulphate of lime and sulphurous acid. By what I have said, you 

 will see that to manufacture either of these articles it is necessary to have sulphur- 

 ous acid gas. This gas is composed of one part sulphur and two parts oxygen 

 chemically combined. This combination takes place when sulphur is burnt in air 

 by the oxygen of the air combining in these proportions with the sulphur. But 

 we experience a difficulty in confining this gas when thus produced, so as to 

 force it into the water. Sulphuric acid contains one part sulphur to three parts 

 oxygen. Could we extract from it one part of the oxygen, we would have left just 

 what we want — sulphurous acid gas. Fortunately, charcoal when boiled in sul- 

 phuric acid will extract this desired amount of oxygen. This can be done in a 

 closed vessel, where the heat will force the gas thus formed with great power 

 wherever we wish. Hence, the machine is very simple : a closed vessel with an 

 exit large enough and long enough to convey the gas to the bottom of a barrel of 

 water. If we desire a very pure article, a wash-bottle can be easily attached. The 

 great difficulty to be overcome is to prevent the acids from destroying the machine. 

 But glass, rubber, lead, cast-iron and other things are but slightly subject to the 

 action of these acids. With these we can invent a machine cheap and durable. 

 The principal part of the machine is the retort. All other parts can be easily sup- 

 plied, changed, or repaired at any village at a slight cost. But if your retort fails^ 

 you are done for the season, unless you go to those who manufacture this especial 

 article. We can ill afford to lose the time in the midst of the cane harvest. Be- 

 sides, we will have to pay more than tAvo-thirds the jirice of a new machine for a 

 retort alone. All points of superiority claimed for other parts of the machine are 

 insignificant to those of the retort. The best material for a retort is cast-iron. In 

 this there are but four things to guard against: 



1. Be sure the sides are one-half inch thick where the fire strikes it. 



2. Have it warranted, if possible, to contain no sand-holes. Most of you are 

 aware that I am the inventor of one of these machines. The first retort sent from 

 the shop had sand-holes, and gave out quickly in two places. Having the tools at 

 hand, I quickly and permanently repaired it by boring out the sand-holes and fill- 

 ing them with rivets; but to most of operators this could not be so readily done, 

 and might result in great loss. Word was immediately sent to the shop that no 

 more retorts with sand-holes would be received. Not a single complaint has been 

 made by any of the patrons of the company, though many retorts were sent out 

 and diligent inquiry has been made. Lettei-s have reached me stating that retorts 

 sent out by other parties were honey-combed by sand-holes, showing the necessity 

 of a guarantee against this evil. 



3. Have the rubber packing near the top and in a neck of the retort, and well 

 secured by a sufficient number of bolts with deep threads, or it will keep one hand 

 busy to keep the gas from leaking, and then fail. 



31— Agriculture. 



