PREPARATION AND MOUNTING 



easy matter to obtain interesting specimens of Foraminifera. 

 Scrape a small quantity of chalk from the mass and shake 

 it in water ; leave this a few minutes, pour the water away 

 and add a fresh quantity, shake up as before, and repeat 

 two or three times. Take a little of the residue, and spread 

 it upon the slide, and when quite dry, add a little turpentine. 

 When viewed with a power of two hundred and fifty dia- 

 meters, this will generally show the organisms very well. 

 If it is desired to preserve the slides, they may then be 

 mounted in Canada balsam. Mr. Guyon, in " Recreative 

 Science," observes that the accumulation of the powder, by 

 the action of the rain or exposure to the atmospheric action, 

 at the foot or any projection of the chalk cliffs, will afford 

 us better specimens than that which is scraped, as the 

 organisms are less broken in the former. 



Take a piece of chalk, and with a soft tooth or nail brush, 

 brush it under water, and then wash the sediment well till 

 the water is not coloured, when the residue will be nearly 

 all Foraminifera. 



The above is the most simple method of obtaining Fora- 

 minifera from chalk, but is not so satisfactory when any 

 number of perfect slides is wanted for the cabinet. I shall, 

 therefore, give additional particulars from the experience of 

 good men. But some specimens of chalk seem to have 

 undergone such powerful action that no perfect forms are 

 found in them. This accounts for that disappointment 

 which I have now and then heard expressed. One student 

 says, Take about one ounce of chalk, place it in a 

 quart bottle with about a pint of water, shake it, and after 

 a few moments pour off the milky fluid to about one fourth. 

 Add more fresh water, shake and pour off, waiting longer 

 each time for it to settle. Continue ten or twelve times in 

 one day, and repeat two or three times a day for a few days, 

 and the result will be a sediment entirely composed of 

 Foraminifera. If fragments of chalk remain, the bottle has 

 not been sufficiently shaken. 



Mr. Kobertaon uses a somewhat different method. Break 



