392 GIBBS, AGCAOILI, AND SHILLING. 
about 1,000 to the receptacle. The top is usually covered with 
an empty sack and a layer of rice husks. The bamboo cylinders 
containing the eggs are surrounded by rice husks. Twice each 
day at 6 o’clock in the morning and 5 o’clock in the afternoon 
the eggs are repacked, probably for the purpose of turning them 
over and also to allow the entrance of air and heating the rice. 
Plate II, fig. 2, illustrates this form of incubator. After eighteen 
days of incubation, the eggs are boiled in water and sold as balut. 
Large numbers of ducks are hatched in a slightly modified 
form of the same apparatus. When it is desired to carry the 
incubation process to completion, the balut stage is first carried 
on as described, after which more care is used and only single 
layers of eggs are packed in the unhulled rice. The eggs are 
not completely buried in the rice, but are covered with sacking 
and a thick layer of rice hulls, and in this case the turning and 
repacking process is carried on three times each day, every four 
hours during the daytime. The eggs hatch in about thirty-three 
days. The operation of turning the eggs is illustrated in Plate 
Ill, fig. 1. 
A household industry of making balut and hatching the eggs 
by means of the heat of the human body was formerly more 
extensively engaged in than at present. The eggs were put in 
racks under the chairs, or under beds and sometimes in belts 
which were fastened around the waist. The health officials have 
been instrumental in discouraging these practises. 
Konig gives the constituent of hen’s and duck’s eggs as 
follows: 
TABLE VIII.—Weight and percentage of yolk albumen, and shell 
in hen’s and duck’s egys. 
Hen’s egg. Duck's egg. 
| 
Constituent. 
Grams. eae Grams. | Per cent. 
Wieirht ofioneltep pr) =o- encase | SOIEOn 25] eee | 60"| = 3-38 
| Wolltonsa.5 ste cea ee eee nae | 10 to 28 30.0 24 | 40 
WAibumen-o 0. pena eater eee td 15 to 43 58.5 | 30 | 50 
Shells. 5). 22 occ 8 ee SE eee 3to 7 11.5 | 6 | 10 
*° Chemie der menschlichen Nahrungs- und Genussmittel. Berlin (1904), 
2, 573. See also 1, 99 and 1471. 
