1896 THE MICROSCOPE. 189 



and cover. Then heat until the fluid flows and fills the 

 space under the cover. Use a little less balsam than seems 

 necessary. A little pressure on the cover will spread the 

 balsam to the edge. 



How to Obtain Paste Eels. — Paste eels are undoubt- 

 edly fattened vineg-ar eels. These objects are always inter- 

 esting- to exhibit to friends. It is not as easy to procure 

 them from the limpid vineg-ar as from the thicker paste. 

 In the vineg-ar they are too active and dart too rapidily 

 from the field ; in the paste they become fat, larg-e and 

 slug-gish and remain in the field. For their production, 

 make some boiled flour paste; add to this a few drops of 

 cider vineg-ar and in a few days the paste will teem with 

 the eels. Be sure that the added vineg-ar contains eels; to 

 do this, hold the vineg-ar cruet between yourself and a 

 strong- lig-ht and examine with a pocket lens. In the drops 

 of vinegar added to the paste, secure as many eels as pos- 

 sible. Keep the supply in an uncorked, open-mouthed 

 bottle with as broad a base -is possible. 



SCIENCE-GOSSIP. 



How Roquefort Cheese is Made. — It is supposed that 

 hundreds of years ag-o the South of France was disturbed 

 by volcanic eruptions, which slit up the ancient granite 

 rock causing streams of lava to flow from them. The new 

 surface consists of basaltic rock, which in its turn was 

 fissured by eruptions and thrown up on a mountain range. 

 The whole of the interior of a mountain was thus formed 

 into caverns and caves, which belch forth hot sulphurous 

 springs. It is here that the celebrated Roquefort cheeses 

 are made. The village of Roquefort is situated on the 

 Mountain Larzac, which is about twenty-five miles in 

 length and nearly 3,000 ft high. It consists chiefly of lime- 

 stone, covered with sufiicient pasture to feed the 300,000 

 sheep kept for their milk. The caves, being formed by 

 the displacement of rocks, consist of an intricate laby- 



