MICROS' 999 



::x Mu.ple apparatus b all that it 

 absolutely needful, though if a grinding- machine be 

 added it will save time and labour. If slide* of extreme 

 thinness are re * beat obtained from a 



specially trained lapidary or dca 



\tra/*t/t>r tkt fr</*ratiom <j fkim tlitti o/ nxks 

 ami minerals /or mitreutpual tx ami nation. 



i A out iron plate, | inch thkk tad 9 inchr* tqua 



a. Two pieces of plate-gla**, 9 inches square. 



3. A Water of. Ayr none, 6 inches long by >| inches broad. 



4. (*oane emery (lib. or to at a time}. 



: floor emery (.!. 

 6. Putty jxmdcr (I at) 



anad* bmlamm. (There is an excellent kind prepared by 

 K.mmingion, Bradford, especially for miooacopic prqwira- 

 lions, and told in shilling bottle*.) 

 8. A small forceps. 



>ome oblong pieces of common flat window-glas*; 



inches b a convenient sbe. 

 I a Glasses with ground edges for mounting the dices upon. 



They may be had at any chemical instrument -maker in 



different sices, the commonest being JX I inches. 

 1 1 . Thin covering-glasses, square or round. The* are sold by 



the ounce ; | ounce will be sufficient to begin v 

 1 3. A unall bottle of spirit* of wine. 



The first process . n rubbing down and polish- 



ing one side of the chip or slice. We place the chip 

 upon the wheel of the grinding machine or, (ailing that, 

 upon the iron plate, with a little coarse emery and water. 

 If the chip is so shaped that it can be conveniently 

 pressed by the finger against the plate and kept there in 

 regular horizontal movement, we may proceed at once to 

 rub it down. If, however, we find a difficulty, from its 

 small sue or otherwise, in holding the chip, one side of 



