28G Mr, Brooke on the [Oct. 



Phosphate of Soda, 

 Tliis salt effloresces so readily, that if it be attempted to be 

 measured in a warm and dry day, the planes will become obscure 

 before they can all be adjusted on the goniometer.* 



The primary form is an oblique rhombic 

 prism, with indistinct cleavages parallel to 

 the planes M and M'. The crystals are 

 frequently deposited singly and very sym- 

 metrically formed. 



PonM, orM' 106* 44' 



Pone' 129 12 



Pong 112 27 



Vonh 121 14 



MonM' 67 30 



MonA 123 45 



Men k 146 15 



Succinate of Ammonia, 



Cleaves readily parallel to the planes P, M, and T, of a doubly 

 oblique prism. The attachment of the crystals is commonly by 

 one of tne summits of the figure. 



PonM 91° 53' 



PonT 93 



Pon^* 91 



P ong 151 



Pon/ 151 



MonT 100 



Mong 119 



Mon/' 117 



T on A 135 



25 



45 



57 



7 



15 

 53 

 00 

 46 



Succinate of Soda, 

 The primary form is a doubly oblique prism^ of which either 

 the plane marked P, or that marked Z>, might be the terminal 

 one. There is not any distinct cleavage that I can perceive 

 parallel to either of these, or to the lateral planes, although there 

 IS some trace of it parallel to b. Some of 

 the crystals have both their terminations y 



complete. ' "- 



P on M 128° 00' 



P on T 140 50 



P on A' 99 30 



Pon A 169 55 



MonT 117 6 



T on A- 133 20 



bonU 115 8 



6onT 108 7 



• It need scarcely be remarked that efflorescent Baltt should be measured when the 

 air ii moist, and deliquescent ones when it ia warm and dry. 



