294 SORGHUM. 



up the juice, and several slips of fresh litmus paper, previously red- 

 dened by dipping them in fresh juice, should be right at hand. 



The lime should be added gradually, with constant stirring, in order 

 that it may be thoroughly distributed through the mass of liquid, and 

 repeated tests are to be made with the litmus paper, until the reddened 

 litmus is turned purple, but not blue ; since that would show that to;) 

 much lime had been added. The turmeric paper v»ould show a faint 

 brownish-red, instead of the yellow, which is its color, in juice which 

 had received the right amount of lime. As the amount of lime which 

 is approximately correct will soon become known, the additions at 

 first may be more rapid than at the close; but, as the point vS neutral- 

 ization is being approached, the greatest care should be exercised to 

 avoid an excess. Should too much Yime be accidentally added, a little 

 more fresh juice may be brought into the defecator, although, with 

 care, this will very rarely be necessary. 



Owing to the impossibility of having the samjjles of cream of lime 

 of the same strength, as also the difference in the acidity of juice, it is 

 impossible to lay down any exact rule as to quantity to he added ; and 

 the good defecator will always proceed wiih caution, until experience 

 has taught him how to advance more rajnilly. But, with an ordinary 

 defecation of from 300 to 500 gallons of juice, there is always ample 

 time to complete the addition of the lime before the boiling p;)int is 

 reached. So soon as the proper amount of lime has been added, the 

 juice should be left at rest, and the heat increased to bring the whole 

 to the boiling point. 



The following phenomena will appear in a good defecati m : As the 

 temperature increases, a dark green scum Avill rise upon the surface, 

 and, if a portion of it is pushed aside, a heavy, flocculent precipitate 

 will be seen distributed throngli the clear and almost colorkss j'lice. 

 The scum will increase in quantity, and gradually grow darker in color, 

 and more compact, resembling a thick " blanket," as it has been termed. 

 Shortly after, seams will f)rm in the scum ''cracking," and here 

 and there the juice (now about reaching the boiling jioint) will bubble 

 up through points in these cracks, showiug a perfectly white foam. So 

 soon as the boiling point is reached, and before the scum has been 

 broken up by boiling, the steam is wliolly turned off, or the fire is with- 

 drawn. And here is one of the great advantages of steam, that the 

 lieat may be almost instantaneously witlulrawn. If direct heat is used, 

 care should be exercised that the fire be nearly through, by this time, 

 and the heat, at the last, urged by a few sticks of light wood, which 

 may be easily quenched. The object of preventing tlie boiling of the 



