QUANTITY OF OIL FURNISHED BY THE SEEDS OF FOREST-TREES. 237 



We may remark that when a large amount of colouring matter is 

 present, it will be found difficult to distinguish the colour of the pre- 

 cipitate, we find it advisable to have the solution pretty dilute, and 

 partly precipitate the tannine with ordinary gelatine solution, the preci- 

 pitate in falling will act as a decolorizer, and render the experiment quite 

 easy to perform. 



We append our results, arranged in a tabular form, for convenience of 

 reference : — 





Quantity of 



Tannine 

 in 100 parts. 



Loss on the amount of Tannine in 

 100 pts. after standing a week. 



Name. 



In Solution 



standing by 



itself. 



In Solution di- 

 gesting on undis- 

 solved Residue. 



Chloroxylum excelsum Bark 

 Mangrove Bark .... 

 Terminalia angustifolia . 



Tamarisk Galls .... 



3.780 



2.150 



6.621 



1.758 



40.660 



18.230 



87.980 



9.086 



55.568 



76.590 



26.000 



17.460 

 .440 

 5.280 

 .384 

 4.200 

 9.100 

 1.250 



16.80 



1.00 



4.17 



.10 



The investigation was conducted in the Laboratory of the Museum of 

 Irish Industry, under the direction of Mr. Galloway. 



QUANTITY OF OIL FURNISHED BY THE SEEDS OF VARIOUS 

 FOREST-TREES. 



BY M. R. WAGNER. 



I have conducted a series of experiments to ascertain the quantity of 

 oil contained in the seeds of various forest-trees. These seeds were passed 

 through an oil-press, mixed with sand or powdered quartz, dried to 1 00°, and 

 drained of a little of the bi-sulphide of carbon ; afterwards, the remaining 

 sulphide of carbon was separated by exposure to the air, and elevating the 

 temperature in a water-bath. The following were the results obtained : — 



Beech-nuts, or mast, yielded the following percentages of oil :— - 

 Seeds collected in 1857 23.2 



1858 



1859 Specimen a 

 b 



25.0 

 19.3 

 22.6 

 18.9 



