| Castor oil imported. lbs. | Retained. lbs. | |
| 1826 | 263,382 | 453,072 |
| 1831 | 393,191 | 327,940 |
| 1836 | 981,585 | 809,559 |
| 1841 | 871,136 | 732,720 |
| 1846 | 1,477,168 | — |
| 1849 | 1,084,272 | — |
| 1850 | 3,495,632 | — |
The imports of castor oil come chiefly from the East India Company's possessions, and were as follows, nearly all being retained for home consumption:—
| lbs. | |
| 1830 | 490,558 |
| 1831 | 343,373 |
| 1832 | 257,386 |
| 1833 | 316,779 |
| 1834 | 685,457 |
| 1835 | 1,107,115 |
| 1836 | 972,552 |
| 1837 | 957,164 |
| 1838 | 837,143 |
| 1839 | 916,370 |
| 1840 | 1,190,173 |
| 1841 | 869,947 |
| 1842 | 490,156 |
| 1843 | 717,696 |
In 1841, 12,406 Indian maunds of castor oil were shipped from Calcutta alone, and 7,906 ditto in 1842.
In 1842, 8 cases were shipped from Ceylon, 10 in 1843, 24 in 1844, and 14 in 1845.
1,439 barrels were shipped from New Orleans in 1847. The quantity brought down to that city from the interior was 1,394 barrels in 1848, and 1,337 barrels in 1849.
Within the last year or two, an attempt has been made to introduce the cake obtained in expressing the seeds of the castor oil plant as a manure, which is deserving attention, both because it is in itself likely to prove a serviceable addition to the list of fertilizers which may be advantageously employed, and because it may lead to the use of similar substances, which are at present neglected, or thrown aside as refuse.
The castor oil seed resembles in chemical composition the other oily seeds. It consists of a mixture of mucilaginous, albuminous, and oily matters; and the former two of these are identical in constitution and general properties with the substances found in linseed and rape cake, while the oil is principally distinguished by its purgative properties. The cake obtained is in the form of ordinary oil-cake, but is at once distinguished from it by its color, and by the large fragments of the husk of the seeds which it contains. It is also much, softer, and may be easily broken down with the hand. I have analysed two samples of castor cake, stated to have been obtained by different processes; and though I have not been informed of the exact nature of these processes, I infer, from the large quantity of oil, that one must have been cold-drawn. The first of the following analyses is that of the sample which I believe the cold-drawn. It is the most complete of the two, and contains a determination of the amount of oil. In the other analysis this was not done, but there was no doubt on my mind that its quantity was much smaller.