CONTENTS. xv 



$ 22. Sweet Mercury ^ page 359 



23. Methods of preparing it 360 



24. In 'what Way the ancient Chcmijls pro- 

 ceeded in refpett to fweet Mercury 365 



25. P by fical Qualities offwect Mercury 366 



26. Siveet Mercury diffbhed by various 

 Fluids 368 



27. Procefi for preparing corrojive Mer- 

 cury from fweet Mercury 369 



28. How it happens that the cor ro five Force 

 offaJited Mercury it not a! ways the fame 



37 

 a 9. The various fffei of the Mercurial fain 



373 

 VII. PROCESS for BURNING BRICKS. 



5 I. Circumtlances which fuggejled the fol- 

 low iig Experiments, and the Dpfgn 

 with which they are communicated 376 

 i. The different Sorts of Bricks - 377 



3. The ordinary Faults of Tiles - 378 



4. Pure Clay '. V 379 



5. Common Clay - 380 



6. 7/ou; Bricks fiould he formed and burnt 381 



7. Attempts to im^iyve Clay by the inter- 

 mixture of other Subjlanccs are of no 

 Service - * - 383 



8. Experiments of the Author - .. 384 

 f). Advice relative to the burning of bricks 385 



{o. Methods ofajfiiying C/ayfor Tiles 386 



VIII. Of 



