134 The Microscope, 



carmine, 10 grs. ; ammonia, 10 grs. ; water, 2 oz. The carmine is to 

 be dissolved in the ammonia over the flame of a spirit lamp, the water 

 added next and the fluid filtered before it is used. Put the sections 

 in this stain for eight or ten hours, then take them out and wash in 

 not more than two changes of water, and finally transfer them to 

 the green stain. For this take aniline green, three grains ; absolute 

 alcohol, one oz. Dissolve in a test tube, using slight heat only, and 

 filter before using. 



Put the sections in this stain for three or four hours, and 

 then mount without delay, after having washed the superfluous 

 color away with methylated spirits. The sections having been well 

 washed, are soaked in absolute alcohol for an houi", then removed to 

 oil of cloves, and allowed to remain in this for about twenty- 

 five or thirty minutes. At the end of this time transfer them to oil 

 of turpentine for abou.t the same time. They are then ready for 

 mounting in balsam or damar. 



Staining in picro-carmine is the most truly selective of any 

 double stains yet employed. A special modification of the usual 

 formulae is required for wood sections, as follows : 



Picro-Carmine Solution — Carmine (finest), 2 grains ; liquid 

 ammonia, one- half drachm ; distilled water, 1 oz. 



Put the carmine in a two ounce stoppered bottle, pour in the 

 liquid ammonia and shake occasionally until dissolved, then add the 

 water. 



Picric acid, 8 grains ; alcohol, 1 oz. 



Dissolve the picric acid in a test tube, using gentle heat ; then 

 mix with the solution of carmine. 



Wood sections stained in picro-carmine are very beautiful, the 

 structures being well differentiated. Sections thus prepared are 

 soaked in alcohol for a short time and then removed to clove oil and 

 mounted in balsam. 



THE MOVEMENT OF DIATOMS. 



CORNELIUS ONDERDONK. 



THE first visible manifestation of life is motion. Whence this 

 mysterious motion or how it first seizes on dead matter we 

 may never know. This, howevei-, the microscope reveals — that motion 

 is the first sign life gives to the intelligence of man. 



The mysterious substance called protoplasm lies at the very 

 portal of differentiation ; behind this form of matter the' wisdom of 

 man has not yet penetrated, and, indeed, although he calls this form 



