Nov. i, 1894.] THE TROPICAL AGRICULTURIST. 297 
CEYLON MANUAL OF CHEMI- 
CAL ANALYSES. 
A HANDBOOK OF ANALYSES CONNECTED WITH 
THE INDUSTRIES AND PUBLIC HEALTH OF 
CEVLON FOR PLANTERS, COMMERCIAL MEN, 
AGRICULTURAL STUDENTS, AND MEMBERS OF 
LOCAL BOARDS. 
By M. COCHRAN, M.A., f.c.s. 
f Con eluded from page 227. ) 
APPENDIX— ( Continued.) 
Analyses of four samples of the Coals used by the 
Colombo Gas and Water Coy., Ltd., during 1893. 
Description of 
Coal. 
Gas Coal. 
Steam 
Coal. 
Source of Coal. 
Austra- 
lia. 
Bengal, 
Assam. 
Cardiff. 
Volatile mat- 
ters 
Gas, tar, &c. 
Sulphur ... 
Water 
Coke 
P'ixed carbon 
Sulphur ... 
Ash 
percenti 
(35-5) 
32 515 
•245 
2-740 
(64 -5) 
56919 
•441 
7-140 
percent. 
(36-00) 
33-18 
•12 
2-70 
(64-00) 
53-14 
•22 
10'64 
percent. 
(39-35) 
35-29 
•62 
3-44 
(60-65) 
5186 
•95 
7-84 
per cent- 
(16-7 ) 
1531 
13 
1-26 
(83-3 ) 
81-68 
•62 
1-00 
100-000 
100-00 
100-00 
100-00 
Specific gravity 
Heating power 
in unite 
Weight per cu- 
bic foot iu lbs. 
Colour of Ash 
1 -363 
8-400 
85-187 
Light 
brown 
1-363 
7-938 
85-187 
Light 
grey 
1 -304 
7-834 
81-500 
Keel 
1-304 
11-088 
81-500 
Red 
The above represent the composition of the coal 
proper, and judging from the results the Assam 
coal might be expected to yield most gas while 
the Bengal might be also expected to shew a 
slightly higher yield than the Australian ; but 
in practice the Australian coal gave the best 
results and the Bengal next best, the reason being 
that the Australian coal was freest from stones 
and dirt, and the Bengal cleaner than the Assam. 
The Cardiff coal was not used for its gas-produ- 
cing power which is small, but for its heating power. 
The analysis brings out its marked superior- 
ity in the latter respect to the others shewing, as 
it does, nearly 25 per cent more fixed carbon. The 
heating power is expressed in terms of units 
(say pounds) of water at 212°F converted into 
steam by the consumption of one unit (say 1 lb. ) 
of tho coal. The heating power may therefore 
be also termed the steam-producing pow er of the 
coals, 
86 
Chemical Examination of a sample of Chehku 
Coconut Oil. 
Specific gravity at 84°F.( water at 60°F. = 
1000) ... ... -. 916-1 
Specific gravity at 212°F. (water at 60°F. 
= 1000) ... ... ... 872-4 
Iodine absorption, expressed in centi- 
grams of iodine absorbed per gram 
of oil ... ... v . 8-49 
Saturation equivalent, expressed in 
centigrams of caustic potash required 
to saturate fatty acids in one gram of 
oil ... ... ... ... 26-92 
Free fatty acids in oil, per cent ... T97 
Insoluble fatty acids in oil, percent ... 91-38 
Soluble fatty acids in oil, percent ... 1'15 
Unsaponifiabfe oil, per cent... ... '20 
Note on Specific Gravity* 
The specific gravities deteimiued by the author, 
in connection with milk and oils, represent 
when not otherwise stated, the weight of a 
given volume of milk or oil, at the observed 
temperature, compared with the weight of an 
equal volume of distilled water at the same 
temperature. In the case of milk, the specific 
gravity thus determined gives a close approxima- 
tion to what it would be at standard temperature. 
In Colombo there is a drawback to the determi- 
nation of the specific gravity of liquids after 
cooling them to the standard temperature of 
15-5°C. or 60°F., as the moisture of the atmosphere 
at this low temperature condenses on the surface 
cf the specific gravity bottle, during the operation 
of weighing. Some liquids also, for example, 
coconut oil, when cooled, change their physical 
condition from liquid to solid long before the 
standard temperature is reached. The true speci- 
fic gravity of liquids at the high temperatures 
prevailing in the tropies, i.e., the weight of a cer» 
tain volume of the liquid at the observed tempera- 
ture, compared with the weight of an equal volume 
of water at standard temperature, may be deduced 
from the specific gravity determined as above des> 
oribed, by multiplying this result by the factor 
opposite the observed temperature as in the 
following table. We cannot, however, calculate 
the specific gravity of a liquid at standard temper-* 
ature from the observed weight of a given volume 
at any higher temperature unless the co- efficient 
of expansion of the liquid be known. 
Table of the Specific Gravity of Water at 
various Tcnvperatures. 
Temperature. 
Specific 
gravity. 
Temperature. 
Specific 
gravity. 
15° C. 
1 '00000 
26° C. 
•99778 
20° C. 
•99918 
27 a C. 
•99752 
21° C. 
•99897 
28° C. 
•99725 
22- C. 
■99875 
29° C. 
•99697 
23 C. 
■99852 
30° C. 
•99668 
24° C. 
•99828 
100° C- 
•95953 
25° C. 
•99804 
Mil!:. 
Although the milk generally sold in Colombo, 
especially in the poorer districts, is a weak in- 
nutritious fluid consisting largely of added water, 
there is no doubt that milk of first-rate quality 
can be produced in Colombo. The following 
analyses of samples of milk drawn from a Colombo 
dairy shew that, if the legitimate industry were 
encouraged by the suppression of fraudulent com- 
petition, Colombo might become as conspicuous for 
the excellence, as it has hitherto been for the, 
poverty of the milk *old to its inhabitant- 
