OF MICROSCOPIC OBJECTS. 7& 



under the microscope with the camel-hair pencil or other- 

 contrivance, as it is impossible to obtain them fit for mount- 

 ing without undergoing this process. 



The eea soundings taken by order of Government are 

 drawn from the bottom in a kind of apparatus ingeniously 

 made for the purpose, and the sand, mud, &c., are brought 

 up in their original state. Common soundings, however, 

 are taken by lowering a heavy piece of lead coated with 

 tallow, which consequently brings up a small portion of the 

 matter from the bottom. Mr. George Mosley, the late 

 Secretary of the Manchester Microscopic Society, obtained 

 numbers of the "scrapings" from the sounding leads. To- 

 make any use of these it is, of course, necessary to free them 

 from all traces of the tallow. Mr. Dancer places the sound- 

 ing in a basin and pours boiling water upon it, which causes- 

 the melted grease to rise to the surface. When cold, this 

 may be removed, and the water carefully decanted. The- 

 operation may be repeated until no grease appears, when 

 the water may be withdrawn and liquor ammonias used, 

 which will form a soapy solution with any remaining grease. 

 This must be treated with hot water for the final washing. 

 Care must be taken lest the finer forms be carried away in 

 decanting the washing liquid. Should it be wished to make 

 certain as to this point, each washing should be examined 

 under the microscope. In some cases the process of Mr. 

 Dancer will prove sufficient. Mr. Dale, however, gives a 

 method of accomplishing the same result, which is much 

 more readily completed; and as no fault can be found with 

 these results, I will here give it in full : It is now well known 

 that one of the products obtained from the naphtha of coal- 

 tar is a volatile, oily substance, termed benzole (or, by 

 French chemists, benzine), the boiling-point of which, when 

 pure, is about 180 Fahrenheit, and which is a perfect 

 solvent of fatty substances. In a capsule, previously 

 warmed on a sand-bath, Mr. Dale mixes with the tallow 

 soundings some of this benzole, until diluted so as to run 

 freely, pressing the lumps with a glass rod until thoroughly 



