CRYSTALLINE (HARDENING OF). 349 



several litres of 1 per cent, bichromate of potash solution, 

 which is frequently changed for stronger solutions until the 

 strength of a cold saturated solution is attained. The bulb 

 must remain in this for at least a year and a half, in order 

 that the crystalline may attain the right degree of hardness. 

 For Maceration, use Max Schultze's sulphuric acid solution, 

 supra, 546. 



