12(i SELErTEl) NOTES FIJO.M 



3rd. — By varying temperature during the process of formation. 

 4th. — Fusion by heat. 



5th. — By the addition of celluloid matter to the solution (]jre- 

 ferably Silicate of Soda as being inorganic and 

 exceptionably stable). 

 6th. — By stirring the solution during evaporation, or allowing 



it to remain quiescent. 

 7th.-- By allowing particles of dust on the slide to act as 

 nuclei, around which acicular crystals may gather 

 in stellate groups. 

 8th.— By the state of the surrounding atmosphere- - moist — 

 dry — or charged with vapour of ammonia — 

 sulphur — alcohol — benzole, etc. 

 9th. — By colouring solutions with magenta, etc. 

 10th. — Compound forms of double and treble salts and sub- 

 stances. 

 nth. — By dropping a saturated solution of a salt not soluble 



in alcohol into alcohol. 

 1 2th. — Gradual change occurs occasionally, sometimes soon 

 after mounting, sometimes after the lapse of years. 

 From this it will be seen what a wide field there is for easy 

 and pleasing experiment, especially as I have by no means ex- 

 hausted the methods of modification, but only suggested a number 

 of them for selection and application to such substances as may 

 be suitable. W. Teasdale. 



Mounting Crystals in Castor Oil. — It is very odd that special- 

 ists wh(j work at chemical preparations do not find out something 

 nicer and not so greasy as Castor Oil to mount these crystals in. 

 My stomach turned against it from the very first, and led me to 

 adopt various dodgy ways of getting mine safely embalmed in 

 balsam. W. Teasdale. 



[It is much to be regretted that Mr. Teasdale has not made 

 known to the Society so;/ie, at least, of his various " dodgy ways '' 

 by which slides of crystals may be " safely embalmed in balsam " ; 

 we have studied the question for the last 1 5 years, and have not 

 yet found a solution ai)plicable to every kind of crystal. — Editor.] 



Stauroneis fulmen. Not being a " Diatomaniac," I cannot go 

 into extacies over this solitary Lilliputian's tip-cat, despite its im- 

 posing name and dignified isolation, and am so ignorant in the 

 matter of diatoms as to call all these double-enders simply Navi- 

 cular or little boats. Many learned i)articulars about Gyrosigmas, 

 Pleurosigmas, etc., are doubtless to be found in the scattered 

 " Transactions of the (unincorporated) Society for the Confusion 

 of Useless Knowledge," and when "diffraction gratings" have 



