REPORT OF THE CHEMIST. 



335 



Table IV. — Analyses of press cakes. 



"No record was kept in house of the quantity of juice recovered by 

 the presses. In fact it would be quite difficult to determine just the 

 proportion of the juice flowing from the presses that would be lost in 

 ordinary work. 



This season we found it necessary to em^ty one press once for every 

 2,889 gallons of juice expressed by the mills. The total amount of 

 juice was 1,271,205 gallons, hence the number of presses of press- 

 cake was 1,271,205-^2,889=440. The average weight of the press-cake 

 per press was 330 pounds, 830x440=145,200 pounds of press-cake for 

 the entire season. The amount of press-cake per ton of cane was 

 20.15 pounds. 



In the work with the experimental * press in 1884, on thoroughly 

 drained ^'blanket" scums, the yield of juice was 80 per cent. The 

 average skimmings and settlings after long standing and decantation 

 of the clear juice are much thinner than the blanket, and would yield 

 from 85 to 90 per cent, juice by filter pressing. In order to under rather 

 than over estimate the work of the presses, I will base my estimates 

 on the actual yield obtained with the small experimental press. It 

 may be well to state here that the work on a small scale was no better 

 than with the large ^oresses. 



On the above basis the press cake forms 20 per cent, of the total 

 weight of skimmings filtered; hence 145,200-^20x100=726,000, the 

 total number of pounds of skimmings. These figures show that even 

 on a low estimate 6+ per cent, of the juice is usually lost in the skim- 

 mings. 



As the presses save at least 80 per cent, of this, the saving of juice 

 at Magnolia this season was 580,000 pounds. 



As I have repeatedly stated, I consider this estimate a very low 

 one. I have no doubt but that carefully conducted experiments would 

 show a saving of 970,000 pounds of juice. With the filter-press ar- 

 rangement at Magnolia it is impossible to keep a separate account of 

 juice recovered. 



COMMERCIAL VALUE OF PRESS CAKE. 



The average value of the press cake as given in last season's f re- 

 port was 810.64 per ton; the value of the nitrogen being $4.35, and 

 the phosphoric acid $6.29. 



Considering $10.64 an average valuation, thg press cake this sea- 

 son would be worth $772.46. 



* Bulletin No. 5, p. 59. 

 t Bulletin No. 11, p. 18. 



