144 PROCEEDINGS OF SOCIETIES. 



a capsule, previously warmed on a sand bath, Mr. Dale mixes with 

 the tallow soundings benzole, whose boiling point may be about 

 200°, until sufficiently diluted as to run freely, pressing thelumps 

 with a glass rod until thoroughly mingled ; the solution and its 

 contents are then poured into a paper fdter, placed in a glass 

 funnel ; the capsule is again washed with benzole, until the whole 

 of the gritty particles are removed into the filter. A washing- 

 bottle is then supplied with benzole, and the contents of the filter 

 washed to the bottom until that liquid passes off pure — which may 

 be tested by placing a drop from the point of the funnel on a warm 

 slip of glass or bright platinum, when, if pure, the benzole will 

 evaporate without residue or tarnish ; if grease be present, the wash- 

 ings must be continued until free of it; and after rinsing through 

 weak acid or alcohol for final purification, the calcareous forms will 

 be ready for mounting. 



The filter and its contents may be left to dry spontaneously, 

 when the latter can be examined by the microscope. Should time 

 be an object, rapid drjang may be effected by any of the usual 

 methods ; one of which, recommended by Mr. Dale, is to blow a 

 stream of hot air through a glass tube held in the flame of a 

 'Bunsen's burner. The lower the boiling point of the benzole, the 

 more readily can the specimens be freed from it. A commoner 

 quality may be used, but is more difficult to dry afterwards. 



Pure benzole being costlj", this may appear an expensive process, 

 but, with the exception of a trifling loss by evaporation, the whole 

 may be recovered by simple distillation. The mixture of tallow 

 and benzole is placed in a retort, in a hot water, a steam, or a sand- 

 bath ; the benzole will pass into the receiver, and the tallow or 

 other impurities will remain in the retort. When the whole of the 

 benzole has distilled over, which is ascertained by its ceasing to 

 drop from the condenser, the heat is witluirawn, and the retort 

 allowed to cool, before the addition of fresh materials. Half a 

 dozen to a dozen filters, each with its specimen, can be in process at 

 the same time ; and the distillation of the recovered benzole pro- 

 gresses as quickly as the filtration, which was practically proved 

 on the occasion named. Great caution in the use of benzole is to be 

 taken in the approach of lights to the inflammable vapour. 



After the Foraminifera and calcareous forms have been removed, 

 the residue may be treated with acids and levigation in the usual 

 manner, to obtain siliceous forms and discs, if any ; but to facilitate 

 their deposition, and to avoid the loss of any minute atoms sus- 

 pended in the washings, I would suggest the use of filtration. The 

 conical filter is unsuitable, as the particles would spread over too 

 great a surface of paper ; but glass tubes, open at both ends, such 

 as broken test-tubes, will be found to answer; the broad end- 

 covered with filtering-paper, and over that a slip of muslin tied on 

 with thread, to facilitate the passage of the water, and prevent the 

 risk of breaking the paper ; suspend the tube over a suitable vessel, 

 through a hole cut in thin wood or cardboard ; pour in the washings, 

 which can be thus filtei-ed and then dried. The cloth must be 

 carefully removed, the paper cut round the edges of the tube, and 



