1894 THE MICROSCOPE. 29 



Mexico, reached the Smithsonian Institution and were phiced in 

 a box. They remained undisturbed for two years and three 

 months, at the end of which time they were put into ajar of 

 glass with some chickweed and a small quantity of tepid water. 

 Pretty soon they waked up and appeared quite active. 



QUESTIONS ANSWERED, 



Note.— Z)r. .9. G. Shanks, of Albany, N. K, kindly consents to receive all sorts of ques- 

 tions relating to microscopy , whethey asked l^y professionals or amateurs. Persons of a L 

 f ades of experience, from the beginner upiva> d, are ivelcome to the benefits of this depii>' 

 inent. The questions are numbered Jorjiiture t eference. 



188. What is the best way to reduce, clean and mount the Radio- 

 lariafrom Manitoba f — C. S. 



Boil a piece of this shale with a crystal of sal-soda of equal 

 bulk and a smai 1 quantity of water in a wide test-tube. When 

 the shale begins to break down, flood it with hot water and pour 

 it into another test-tube to deposit. Repeat the above boiling 

 with soda and water on the remaining hard fragments of shale 

 until enough disintegrated material has been obtained. The 

 time of contact with the sal-soda should be as brief as possible 

 because the siliceous radiolaria will be corroded by any long con- 

 tact with caustic alkalies. Collect the sediment into one tube, 

 flood with clean water, allow the sediment to fall, pour away the 

 water, add more, and so on, until the sediment is well washed 

 and free from soda. Remove the water as nearly as possible, 

 add about a half dram of strong nitric acid, boil, drop in a small 

 crystal of potassium bichromate, boil thoroughly, add water and 

 wash as above, until the acid is removed. Examine a drop of 

 the sediment. If the forms are not clean, repeat the boiling 

 with acid and bichromate and wash again as above. There is 

 much fine sand and spicules present which may be removed to a 

 certain degree, by shaking the sediment in a test-tube fall of 

 water and pouring away as soon as the heavier radiolaria have 

 settled, and while the finer particles are still floating. This re- 

 peated several times, will clear the deposit enough to allow a 

 fairly clean mount to be made. Place a drop of the sediment 

 in the center of a concaved slip, or varnish ring cell, dry. add n 

 drop of balsam, boil it gently over a lamp, apply n cover, and 

 harden without pressure. 



