(b) By calculation from the specific gravity of the pulp.—There is a very exact relation between the specific gravity of pulp (determined by the method given above) and the per cent of total solids as determined by drying. The solids corresponding to pulps of various specific gravities are given in [Table 5], or may be obtained from the following formula which is derived from the same table:

Per cent Solids = 228 (sp. gr. of pulp - 1.000) + 19.1 (sp. gr. of pulp - 1.015).

2. BY THE EXAMINATION OF THE FILTRATE

If a sample of pulp of considerable size be thrown on a folded filter, a filtrate is obtained whose composition has a definite relation to that of the whole pulp.

(a) By drying.—The per cent of solids in the filtrate may be determined by drying in vacuo at 70° C, or under atmospheric pressure at the temperature of boiling water.

As in the case of the drying of pulp, a constant relation is found to exist between the per cent of solids in the filtered liquor as determined by drying in vacuo at 70° C., and the per cent of solids as determined by drying at atmospheric pressure at the temperature of boiling water. The per cent of solids in the filtrate obtained by drying at atmospheric pressure, multiplied by 1.125, gives the per cent of solids obtained by drying in vacuo. This relation is shown in detail in [Table 5].

Table 2.—Composition of Whole Tomato Pulps

Sample No. Composition of pulps
Sp. gr. at 20° C. Total solids(a)Insoluble solids
_Per cent__Per cent_
1290 1.0252 5.94 0.66
1291 1.0273 6.54 0.78
1292 1.0234 5.50 0.80
1293 1.0293 7.02 0.74
1294 1.0272 6.48 0.69
1295 1.0361 8.67 0.95
1296 1.0380 9.00 1.06
1297 1.0465 11.20 1.19
1299 1.0417 10.07 1.23
1300 1.0322 7.70 0.93
1301 1.0312 7.36 0.91
1302 1.0310 7.45 0.91
1303 1.0340 8.17 0.91
1304 1.0292 6.88 0.88
1305 1.0371 9.03 1.19
1306 1.0370 8.95 0.98
1307(b) 1.0328 7.86 1.01
1481 1.0449 10.82 ...
1482 1.0444 10.83 ...
1483 1.0464 11.21 ...
1484 1.0423 10.27 ...
1485 1.0347 8.55 ...
1477(c) 1.0610 13.86 ...
1479 1.0411 10.00 1.21
1486 1.0169 4.34 0.62
1491 1.0198 4.97 0.63
1496 1.0341 8.27 1.15
1515 1.0352 8.56 1.15
1529 1.0209 5.11 0.89
1530 1.0252 6.21 0.98
1531 1.0291 7.17 1.08
1224(c) 1.0486 11.22 0.91
1325 1.0327 7.86 0.93

Table 2.—Composition of Whole Tomato Pulps Contd.

Sample No.Filtrate from pulps
Sp. gr. at 20° C.Solids(a)Sugar(d) Acid as citricImmersion
refractometer 17.5° C.
_Per cent__Per cent__Per cent_
1290 1.0233 5.24 2.41 0.58 36.24
1291 1.0252 5.71 3.10 0.53 37.80
1292 1.0211 4.88 2.48 0.49 34.51
1293 1.0276 6.28 3.35 0.61 40.04
1294 1.0256 5.82 3.20 0.55 38.27
1295 1.0340 7.69 4.36 0.67 46.03
1296 ... 8.05 4.47 0.66 46.86
1297 1.0446 10.27 5.61 0.89 56.70
1299 1.0394 9.09 4.96 0.81 51.75
1300 1.0304 6.88 3.55 0.67 42.84
1301 ... 6.68 3.27 0.69 41.56
1302 1.0293 6.61 3.43 0.64 41.76
1303 1.0323 7.29 3.77 0.71 44.65
1304 1.0274 6.20 3.03 0.64 39.74
1305 ... 7.98 4.14 0.82 47.30
1306 ... 8.01 4.71 0.69 47.60
1307(b) 1.0308 6.97 3.79 0.66 43.15
1481 1.0421 9.64 5.15 0.99 54.20
1482 1.0422 9.86 5.62 0.94 54.75
1483 1.0441 10.19 5.67 0.98 56.45
1484 1.0396 9.23 5.42 0.81 52.10
1485 1.0332 7.73 4.35 0.72 45.85
1477(c) 1.0579 12.75 6.55 0.97 67.15
1479 1.0386 8.96 ... ... 51.57
1486 1.0158 3.76 ... ... ...
1491 1.0188 4.40 ... ... 32.67
1496 1.0318 7.31 ... ... 44.86
1515 1.0331 7.61 ... ... 46.20
1529 1.0195 4.54 ... ... 32.96
1530 1.0231 5.42 ... ... 36.31
1531 1.0273 6.27 ... ... 40.09
1224(c) 1.0468 10.33 ... ... 57.62
1325 ... 6.99 ... ... 43.80