APPENDIX 



TO CLEAN MERCURY 



IF only dusty, the mercury should be filtered by pressing 

 it through two or three thicknesses of fine linen, or, better, 

 wash-leather. If oxides are present, the mercury should be 

 stirred into strong nitric acid, then washed very thoroughly in 

 water, dried with filter paper and by warming, and finally filtered. 



METRIC WEIGHTS AND MEASURES AND THEIR 

 ENGLISH EQUIVALENTS 



Ip. (micron) = 0-001 millimetre (33$^ inch, nearly). 



1 millimetre = 0-04 (^) inch. 



25 millimetres = 1 inch. 



1 centimetre = 0-39 inch. 



2-5 centimetres = 1 inch. 



1 gramme = 15| (15-432) grains. 



4 grammes = 1 drachm (apothecaries'), nearly. 



28 grammes = 1 ounce (avoirdupois), nearly. 



1 kilogramme = 2-2 pounds (avoirdupois). 



0-5 kilogramme = 1 pound (avoirdupois), nearly. 



1 cubic centimetre = 16 minims, nearly (16-23 minims). 



3 cubic centimetres = 1 fluid drachm, nearly. 



28 cubic centimetres = 1 fluid ounce, nearly. 

 568 cubic centimetres = 1 pint (f litre). 



1 litre = If pints, or 35 fluid ounces, nearly. 



SOLUBILITIES 



AMOUNT OF SUBSTANCE CONTAINED IN 10 c.c. OF A 

 SATURATED SOLUTION 



Alcoholic solution of methylene-blue . . . 0-068 grin. 



Aqueous solution of methylene-blue . . . 0-646 grm. 



Alcoholic solution of gentian violet . . 0-442 grm. 



Aqueous solution of gentian violet . . . 0-175 grm. 



Alcoholic solution of fuchsin .... 0-292 grm. 



Aqueous solution of fuchsin .... 0-066 grm. 



Aqueous solution of corrosive sublimate . . 0-507 grm. 



