Poxp.—On Citric Acid obtained from Auckland and Tahiti Limes. 405 
Arr. LXVII.—On the Percentage of Citric Acid obtained from Limes grown 
in Auckland and Tahiti. By J. A. Ponp. 
[Read before the Auckland Institute, 15th November, 1881.] 
In the course of my analytic duties I have frequently had to examine samples 
of lime-juice from the Pacific Islands, many of these samples being adulte- 
rated with fresh or sea-water. When making these examinations I have 
often felt the need of a standard sample with which to compare those I had 
to investigate, the only reports I had access to being those of West Indian 
and Sicilian juice. 
Through the kindness of Captain Sinclair, of the schooner “ Sybil,” I 
received a box of fine ripe limes in April last, each fruit being carefully 
wrapped in paper. Of these I took forty, weighing 5 lbs. 12 ozs., and care- 
fully grated off the skins, the weight then being reduced to 5 lbs. 4 ozs. 
These I submitted to expression, the result being forty fluid ounces, or & 
little more than 50 per cent. of the weight of the pulp, though a much larger 
return would be obtained with suitable power. The juice thus obtained was 
of a light sherry colour, cloudy, and of a specific gravity of 1-0412 at 62° 
Fahr. The ash I found a percentage of -845, and its acidimetric value to be 
7-752. About the same period I also received a parcel of limes from the 
Hon. F. Whitaker, grown on his land at Lake Takapuna. These limes were 
very much smaller than those from the Islands. Taking ninety I had them 
carefully peeled, and found the weight to be exactly 41bs, from which I~ 
expressed twenty fluid ounces of juice, still leaving a good deal in the mare, 
which would be obtained with greater power. The specific gravity of this 
juice at 62° Fahr. was 1:0454, the percentage of ash °627, and its acidi- 
metric value 8°13. 
These values compare very favo 
tion, and are as follows :— 
urably with those of European reputa- 
Palermo. | W. Indian. Jamaican. | §. African. . 
Specific gravity of juice | 1044-85 | 1041-30 | 1044-18 | 1044-90 
Percent. of citric acid..| 813 | 796| 866 850 | 
Per cent. of ash.. i -289 “321 401 364 
a ee Renee 0 NE errant cea ee ee eae 
When we consider that the ime grows well here, and from — “ the 
North Cape, it will be seen to what advantage this tree might be cultivated. 
i abundantly, for a large por- 
quiring little care in the raising, and fruiting a 
_ tion of the year the crop would be of magnitude, | dared ae | 
“A suitable prose would be fully fifty per cent. For lime-jnice there is always 
and the yield of juice with = 
