EXPLANATION OF PLATE I. 



Micro-crystalline Precipitates, cf. pp. 14-18. 



Figs. 1 to 6 Tartaric acid. 



Figs. 7 to 12 Hydro-calcium tartrate. 



Fig. 13 Hydro-barium tartrate. 



Figs. 14 to 16 Hydro-barium oxalate, from witherite. 



Figs. 17, 18 The same, from baryto-calcite. 



Figs. 19, 20 Hydro-strontium oxalate. 



Fig. 21 Ferrous oxalate. 



Note. — These crystals vary in size, according to temperature and time 

 of formation, and were not drawn by exact measurement. For the large 

 crystals, figs. 14 to 18, a 1£ inch objective was used ; figs. 19, 20, and 21, re- 

 quired a j ; the others were easily seen with a §. 



