On the Affinities of different Earths for Carbon. 41 



serious objections which have been made to it as a system 

 of botany, professing to lead the young student, step by 

 step, from the threshold to the inmost recesses of the sci- 

 ence. lf.Dr. Thornton will prove that he has been igno- 

 rantly or maliciously misrepresented, and that the work, as 

 far as it has proceeded, has realized the greatness of its pro- 

 mise, the reviewer will take shame to himself, and kiss the 

 rod. Till then he must take the liberty to declare, that his 

 opinion of Dr. Thornton, as a writer, remains unaltered. 

 The work and the review are before the public. Those who 

 understand the subject will decide between them. To their 

 impartial judgment he calmly and respectfully leaves it ; 

 and is at the same time, sir, your constant reader and 

 humble servant, Y. Z. 



IX. Experiments to ascertain whether tKere exists any 

 Affinity betwixt Carbon and Clay> Lime and Silex, se~ , 

 parately or as Compounds united with the Oxide of Iron 

 forming Iron Ores and Iron Stones. By David Mushet, 

 Esq. of the Colder Iron- Works*. 



[Continued from our last volume, p. 398.] 



X o prove that there exists any affinity betwixt clay and 

 carbon, or that the latter unites to the former either by 

 fusion or cementation,' the following experiments were 

 made : 



I. 100 grains of well dried Sturbridge clay were intro- 

 duced into a crucible of the same clay, and exposed in the 

 assay-furnace till the pot began to sink and lose shape. 

 When cold, I found the clay resolved into a neat semi-sphe- 

 rical mass firmly connected together, of a pale straw co- 

 lour, but without any symptoms of fusion. It easily parted 

 from the crucible, and weighed 83 grains. 



II. J 00 grains of the same clay, reduced to a fine powder 

 and mixed with half a grain of lamp carbon, were exposed 

 to a similar heat as No. I. The result was a mass every 

 way the same in point of shape, but the colour was blueish 

 gray throughout the whole. The carbon had completely 

 disappeared, and seemed now only to exist as the colour- 

 ing matter in the clay. A few specks of vitrification were 

 evident upon the surface that had been in contact with the 

 crucible. The mass weighed 81 grains, and had therefore 

 lost in water J 9 grains. 



* Communicated by the Author, 



III. 100 



