386 Mr. Amlin on Roman Stone. 



otiier concerns of less magnitude, all of 

 whom confirm the importance of the 

 process. Gray and Dacru. 



To the Editor of the Monthly Magazine, 



SIR, 



"AVING my time very much oc- 

 cupied in the conducting; of an 

 extensive concern, I have little time to 

 devote to literature ; and did not, on 

 that account, know, that you had ho- 

 noured my improvements, in an applica- 

 tion of Roman stone, with notice in 

 your Journal, until a friend favoured 

 me with a perusal of a number lor June 

 1823, and that of the current month. 



To enumerate the very many purposes 

 to which I have applied this useful dis- 

 covery, would appear like vanity in me, 

 and the length of the communication 

 would be inconvenient to you. I will, 

 theretbrc, svilli your permission, confine 

 my reply strictly to the questions asked 

 by your Haverfordwest correspondent, 

 and content myself with inviting; the 

 curious to inspect, at my depository, the 

 rest. The application of Roman stone 

 to the embellishing and landscape gar- 

 dening, with picturesque objects, is 

 practicable, whether it be for bridges, 

 fountains, temples, statues, busts, or 

 vases, some of which articles I have a 

 large collection of; and, being formed of 

 calcined substances, is as durable as 

 Portland stone. The same composition 

 will be found equally beneficial to rural 

 economy. In cow-houses, it will bo 

 found a most neat and cleanly flooring, 

 that may be washed down with water. 

 Piggeries and pig- baths, &c. may bo 

 forn°ed of this material, so that the 

 whole may be kept sweet and clean. I 

 am not fully able to answer the query of 

 your correspondent respecting compara- 

 tive price between the Roman stone 

 and Portland ; but, on a rough calcula- 

 tion, should suppose from one-eighth to 

 three-fourths of the amoimt ; the garden 

 vases, &c. considerably less than that, 

 and are highly ornamental for the recep- 

 tion of plants in conservatory, &c. 

 Little Titchfield-street, F. Austin. 

 Portland Chapel. 



To the Editor of the Monthly Magazine. 

 SIR, 



IN the third and fourth of my re- 

 cently published Dialogues, I 

 have developed a new theory of electrical 

 and galvanic excitement. I explained 

 it on the principle of the action and 

 re- action of atoms, without requiring 



[June 1, 



the aid of any of those gratuitous 

 fluids which hava reitdertd the modu» 

 operandi of ail these phenomena so in- 

 comprehensible and inapplicable. When 

 1 came to treat of magnetism, that op- 

 probrium on the human faculties, i 

 found that all its mysteries yielded, by 

 considering iron in regard to this excite- 

 ment as [jerforming the same office iu 

 magnetism as the wide range of non- 

 electrics in electricity; or, in truth, as 

 the only non-magnetic ; and I deter- 

 mined, by this amilogy, that magnetic 

 iron is merely a galvanic anangemcnt 

 on the surface of iron or steel.* 



Haviiigexplainedthefoca^phenomena, 

 I ventured into the bottomless ocean of 

 polarity, declination, and inclination, and 

 hazarded some conjectures ; but, as will 

 appear by what follows, failed, where 

 so many have failed before me. Piqued 

 at my error, I have reconsidered the 

 subject, and I now hasten to submit my 

 improved views to the readers of the 

 Dialogues, and others who are inter- 

 ested in tliese most curious enquiries. 



In the first place, I will state what the 

 directive force cannot be, and then sub- 

 mit my views of what it is, with all the 

 deference which the judgment of others, 

 and the diflieulty of the subject, de- 

 mands. 



I conceive tliat the directive power 

 arises from no internal appetite or innate 

 propensity of the affected bar, because 

 this would be to render it sentient. 



I conceive that the direction is not 

 created by distant iron, or either pole 

 would be directed indifferently. 



I conceive that it is no circulation 

 or current from the poles to the equator, 

 or from the equator to the jjoics, because, 

 in either case, the same pohs ivould not 

 be constant in both hemispheres. 



1 conceive that it is not a single ac- 

 tion on either of the poles determining 

 the direction of both; or that any single 

 iniluence, proceeding as a current from 

 the south, determines that of the north, 

 or vice versa, because the phenomena of 

 di[) alternates iu both hemispheres. 



I conceive that it is no current (as has 

 lately 



* That tiie agency and government of a 

 magnet arises from a mere affection of 

 the surface, and an action of that surface on 

 tlie intervening space, as in electricity, is 

 evident from the consideration that its 

 power is the same, however thin be the 

 metal, that it is destroyed by rust, wet, 

 &c. and that its force is as the surface. 



