[114] 



1balf^an='1bour at tbe fliMcroecope 



mitb /IDr* UutCen Mest, jf.X.S., if.lR./llb.S., ^c. 



Crystals of Strychnine.— This slide is not interesting. Lists 

 of excellent objects for the polariscope are to be found in all 

 good text-books on the microscope. It is well that all who work 

 with this instrument should have a good knowledge of them, and 

 have in their cabinets a good illustrative series, but they are nof 

 desirable subjects for our boxes. They reduce to child's play 

 what should be considered as valuable opportunities for mutually 

 imparting and gaining knowledge. Writing as I am now doing, 

 far from home, books, and specimens, I would not be positive, but 

 my belief is that there is nothing specially distinctive in these 

 needle-shaped crystals, and, therefore, no knowledge whatever is 

 to be gained from the inspection of this slide. 



Crystals of Oxalic Acid.— I am quite sure of the correctness 

 of my proposition in this case, which, for anything that here 

 appears, might just as well be crystals of any other salt, so many, 

 when rapidly crystallised from weak solutions, form just such as 

 we see here, and which have nothing whatever of the forms 

 whereby crystals of oxalic acid, or salts isomeric with it, may be 

 recognised when present. Our readers may remember some 

 interesting descriptions, with figures by Lewis G. Mills, LL.B., of 

 Armagh, of crystals found by him in the fang of a spider and in 

 the sting of a wasp. The accounts of these appeared in parts of 

 Science Gossip of a few years ago, and I have myself remarked in 

 these "Notes" on similar crystals present on a slide of " Sting of 

 Scorpion."* These, though probably not exactly oxalic acid, were 

 " isomeric " — that is, identical in form with the typical crystals of 

 that salt, and, as I have already pointed out, illustrate well the 

 application of the polariscope as an adjunct, at times of much 

 importance in scientific investigation. 



Crystals of Sulphate of Cadmium.— The quadrifid, petraloid 

 character of the crystals is, so far as I know, unique, and may, 

 therefore, be considered to have a claim to admission into our 

 boxes. 



Batrachospermum moniliforme is a very remarkable form of 

 alga, and might be compared to such fungi as Peiiicillium or 

 Oidium^ borne in dense whorls ; both stems and branches ex- 



* See this Journal, Vol. III., pages 113, 251 ; also, on Fang of Viper, 

 with plate, Vol. III., PI. 28. 



