m ESSAYS AND OBSERVATIONS 



cryPfalline form, and if they are diffolved in 

 diftilled vinegar, the mixture fpontaneoufly 

 dries up into a friable fait. 

 - Having thus found magnefm to differ 

 from the common dkaline earths, the object 

 of my next inquiry was its peculiar degree of 

 attrition for acids, or what was the place 

 due to it in -Mr.'Gfc^ro)'.'s table of eledive 

 attradions. ■ 'J^'^ ■ . ,;:; h'^Lbc :.. 



TrtREE drani3 ot magnejia'm -fine powder, 

 an ounce of fait ammoniac, and fix ounces- 

 of water were mixed together, and digefled 

 fix days in a retGrt-]oined to a receiver. 



During the whole time, the neck of the 

 retort was pointed a little upwards, and the 

 moft watery part of the vapour, ; which was 

 condenfed there, fell back into its body. In 

 the beginning" of the experiment, a volatile 

 fait was therefore colleded in a dry form in 

 the receiver, and afterwards diffolved into 

 fpirit. 



When all was cool, I found In the retort 

 afaline liquor, fome undifTolved magnefia^ and' 

 fome fait ammoniac cryflallized. The faline 

 liquor was feparated from the other two, and 

 then mixed wich- the alkaline fpirit. A 



