334 DIRECTIONS FOR THE MICROSCOPE. 



Shells. — Minute shells; these form must elegant subjects, and in ge- 

 neral fetch a very high price ; but they may be easily obtiiined by es- 

 amining with a microscope the sand found on the sea shores ; they are 

 used as opake objects, and should be placed on a coloured jiaper that is 

 the greatest contrast to the shell. An enumeration witii figures of most 

 of the minute British shells will be found in INIontagu's Tesfacea Bri- 

 tannica, and Walker's Tcstucea m'muta, 4to. 178i. 



Animulcula. — These animals are so exceedingly numerous that vo- 

 lumes might be ^\'ritI:cn uu them. I shall therefore give only a few 

 brief directions for the best methods of obtaining them in vegetable in- 

 fusions, &c. 



Infusions of Pepper. — Bruise as much common black pepper as will 

 cover the bottom of an open jar, and lay it thereon about half an inch 

 thick: pour as much soft water into the vessel as will rise about an 

 inch above the pepper, shake the whole well together; after which they 

 must be stirred, but be left exposed to the air for a few days, in which 

 time a thin pellicle will be formed on the surface, in which innume- 

 rable animals are to be discovered by the microscope. 



Eels in Paste — may be obtained by boiling a little Hour and water 

 into the consistence of honey, then exposing it to the air in an open 

 vessel, and beating it frequently to prevent tlie surface from growing 

 hard : in summer, after a few days, eels will be found in myriads visi- 

 ble to the naked eye, and may be preserved for a length of time by 

 Jceeping the paste moistened with water. 



Vegetable Infusions. — These as well as animal infusions are by far the 

 best methods of procuring animalcula. Plants should be placed in a 

 glass of either rain or river water, and suftered to remain imtil a scum 

 is observed on the surface of the water, which acquires thickness by 

 standin"-. In this scum the greatest number of animalcules are found. 

 Sometimes it is necessary to dilute the infusions; but this ought al- 

 ways to be done with water, not only distilled but viewed through a 

 microscope, lest it should also have animalcules in it, and thus prove 

 a source of deception. 



Stagnant waters contain also immense numbers of these very mi- 

 nute but interesting animals ; they are also found adhering to duck- 

 weed, pieces of wood, &.c. A quantity of these should be collected and 

 thrown into clean water; they may then be separated and fiu'ther ex- 

 amined. 



Zoophr/tes and Corals. — These are only to be obtained on the sea 

 shore, and are found at the recess of the tide. When an opportimity 

 occurs of collecting in these places, every piece of sea weed, &c. should 

 be examined, as many very rare marine animals are frequently found 

 in them, especially after a storm. 



