1.804. Review of Hints to Agnculturijlr. 217 



The great bulk of the pamphlet is taken up In llluftrajtlng and 

 confirming this moil luminous, and certainly n;oil compendious 



theory, 



cauftic alkaline ftate ; in which ftate, like other alkali^, it greedily ab- 

 forbs water. The efFe<5l of the application of water, whether pour- 

 ed on by man, or abforbed from the moiliure of the atmofpherc, is, 

 to niake the bui,>t limellone crumble into powder with the genera- 

 tion of heat ; and this internal commotion of parts, the author might, 

 with equal propriety, have defigned fermtntation, as the ebullition and 

 effervefcence already mentioned to which he has given that defignation. 

 So long as lime remains in its pure allaline cauftic ilate, diverted of 

 carbonic and of every other acid, it is, like all alkalis in the lame ftate, 

 in rcadinefs to abforb quietly^ and without any fymptoms of our author's 

 fa-mentatio?/^ any acid that is applied to it — excepting indeed the fer~ 

 mentation of crumbling bito poiuder, which the water, in which the acid 

 applied may be difiblvcd, will occafion. Lime, however, cannot re- 

 main long in its cauftic alkajine ftate, but is fpeedily neutralized and 

 rendered mild (or, in faft, it reverts to its original ftate as limeftonc), 

 by reabforbing the carbonic acid that had been expelled by burning, 

 greedily taking it in, in proportion to its expofure of furface : And in 

 this ftate alone is it fufceptible of our author's fer}>.>etitalion^ i. e. the 

 ebullition and effervefceace occafioned by the efcape'of the carbonic acid 

 in an aeriform or gafeous ftate, when expelled by another acid having 

 ftronger affinity to the alkali of lime. 



What, then, does our author underftand by his diftinftion of lime 

 (page 9.) into two kinds; the one, * foft, mild, and hxivial, ' (lixi- 

 vial, according to our interpretation of Englifti, implies a fluid in which 

 any falts are dilfolved) ; the other, * dry, acrid, cauftic?' We know 

 that limeftones differ according to the quantity of the foreign admix- 

 tures they contain of fand, or clay, &c. ; but we certainly conceive it 

 as effentially cliarafteriftic of all lime qua I'wi':^ to be acrid or caujlle 

 (which are tlie fame thing), when new burnt j and to be mild or foft 

 (which we underftand to imply the fame fenfe), fo foon as neutraliza- 

 tion .takes place by faturation with an acid — whether by the fixed air 

 abforbed from the atmofphere, or by any other acid applied. 



What does he mean by teUing us (pages 21 — 23.), that greafr care 

 muft be taken, in liming land, to proportion the quantities of the al- 

 kali to the acid, to fecure the greateft poffible fermentation, and to 

 avoid the exceflive preponderance of either, in fear of defeating this 

 intention, — but that the precife equilibrium, which chemical nicety 

 would feem to require, is not effentially neceffary in practice ; becaufe, 

 * even if the quantity of lime ufed be at almoft any point below ex» 

 treme profufion, its own powers of abforption will precifcly apportion 

 the attraction of atmofpheric acid, and regulate the procefs of fermen- 

 tation ? ' After our previous obfervations above, our readers can judge 

 for themfelves. Wc certainly, in the courfe of our reading, have hard- 

 ly met with fuch bulk of ollentatious abfurdity wrapt up in fufl^ 

 fmaU volume. 



