y　and　profit；　not　merely　to　that　country；　but　to　the　human　race；　his　deeds　may　proudly　claim　comparison　even　with　the　most　splendid　of　those　achieved　by　classes　so　rich　in　glorious　recollections。　　An　objection；　in　most　cases　fatal　to　such　a　course；　arises　from　the　impolicy　of　conferring　a　title；　unless　a　considerable　fortune　exists　to　support　it；　a　circumstance　very　rarely　occurring　to　the　philosopher。　　It　might　in　some　measure　be　removed；　by　creating　such　titles　only　for　life。　But　here；　again；　until　there　existed　some　knowledge　of　science　amongst　the　higher　classes；　and　a　sound　state　of　public　opinion　relative　to　science；　the　execution　of　the　plan　could　only　be　injurious。
  SECTION　7。
  OF　THE　UNION　OF　SCIENTIFIC　SOCIETIES。
  This　idea　has　occurred　to　several　persons；　as　likely　to　lead　to　considerable　advantages　to　science。　　If　the　various　scientific　societies　could　unite　in　the　occupation　of　one　large　building；　considerable　economy　would　result　from　the　union。　　By　properly　arranging　their　evenings　of　meeting；　one　meeting…room　only　need　be　required。　　The　libraries　might　either　be　united；　or　arranged　in　adjoining　rooms；　and　such　a　system　would　greatly　facilitate　the　inquiries　of　scientific　persons。
  Whether　it　would　be　possible　to　reunite　in　any　way　the　different　societies　to　the　Royal　Society；　might　be　a　delicate　question；　but　although；　on　some　accounts；　desirable；　that　event　is　not　necessary　for　the　purpose　of　their　having　a　common　residence。
  The　Medico…Botanical　Society　might；　perhaps；　from　sympathy；　be　the　first　to　which　the　Royal　Society　would　apply；　and　by　a　proper　interchange　of　diplomas；　　＇A　thing　well　understood　by　the　INITIATED；　both　at　HOME　and　ABROAD。＇　　the　two　societies　might　be　inoculated　with　each　other。　　But　even　here　some　tact　would　be　required；　the　Medico…Botanical　is　a　little　particular　about　the　purity　of　its　written　documents；　and　lately　attributed　blame　to　one　of　its　officers　for　some　slight　tampering　with　them；　a　degree　of　illiberality　which　the　Council　of　the　Royal　Society　are　far　from　imitating。
  The　Geological　and　the　Astronomical　Societies　nourish　no　feelings　of　resentment　to　the　parent　institution　for　their　early　persecution；　and　though　they　have　no　inducement　to　seek；　would　scarcely　refuse　any　union　which　might　be　generally　advantageous　to　science。
  CONCLUSION。
  In　a　work　on　the　Decline　of　Science；　at　a　period　when　England　has　so　recently　lost　two　of　its　brightest　ornaments；　I　should　hardly　be　excused　if　I　omitted　to　devote　a　few　words　to　the　names　of　Wollaston　and　of　Davy。　　Until　the　warm　feelings　of　surviving　kindred　and　admiring　friends　shall　be　cold　as　the　grave　from　which　remembrance　vainly　recalls　their　cherished　forms；　invested　with　all　the　life　and　energy　of　recent　existence；　the　volumes　of　their　biography　must　be　sealed。　　Their　contemporaries　can　expect　only　to　read　their　eloge。
  In　habits　of　intercourse　with　both　those　distinguished　individuals；　sufficiently　frequent　to　mark　the　curiously　different　structure　of　their　minds；　I　was　yet　not　on　such　terms　even　with　him　I　most　esteemed；　as　to　view　his　great　qualities　through　that　medium　which　is　rarely　penetrated　by　the　eyes　of　long　and　very　intimate　friendship。
  Caution　and　precision　were　the　predominant　features　of　the　character　of　Wollaston；　and　those　who　are　disposed　to　reduce　the　number　of　principles；　would　perhaps　justly　trace　the　precision　which　adorned　his　philosophical；　to　the　extreme　caution　which　pervaded　his　moral　character。　　It　may　indeed　be　questioned　whether　the　latter　quality　will　not　in　all　persons　of　great　abilities　produce　the　former。
  Ambition　constituted　a　far　larger　ingredient　in　the　character　of　Davy；　and　with　the　daring　hand　of　genius　he　grasped　even　the　remotest　conclusions　to　which　a　theory　led　him。　　He　seemed　to　think　invention　a　more　common　attribute　than　it　really　is；　and　hastened；　as　soon　as　he　was　in　possession　of　a　new　fact　or　a　new　principle；　to　communicate　it　to　the　world；　doubtful　perhaps　lest　he　might　not　be　anticipated；　but；　confident　in　his　own　powers；　he　was　content　to　give　to　others　a　chance　of　reaping　some　part　of　that　harvest；　the　largest　portion　of　which　he　knew　must　still　fall　to　his　own　share。
  Dr。　Wollaston；　on　the　other　hand；　appreciated　more　truly　the　rarity　of　the　inventive　faculty；　and；　undeterred　by　the　fear　of　being　anticipated；　when　he　had　contrived　a　new　instrument；　or　detected　a　new　principle；　he　brought　all　the　information　that　he　could　collect　from　others；　or　which　arose　from　his　own　reflection；　to　bear　upon　it　for　years；　before　he　delivered　it　to　the　world。
  The　most　singular　characteristic　of　Wollaston's　mind　was　the　plain　and　distinct　line　which　separated　what　he　knew　from　what　he　did　not　know；　and　this　again；　arising　from　his　precision；　might　be　traced　to　caution。
  It　would；　however；　have　been　visible　to　such　an　extent　in　few　except　himself；　for　there　were　very　few　so　perfectly　free　from　vanity　and　affectation。　　To　this　circumstance　may　be　attributed　a　peculiarity　of　manner　in　the　mode　in　which　he　communicated　information　to　those　who　sought　it　from　him；　which　was　to　many　extremely　disagreeable。　　He　usually；　by　a　few　questions；　ascertained　precisely　how　much　the　inquirer　knew　upon　the　subject；　or　the　exact　point　at　which　his　ignorance　commenced；　a　process　not　very　agreeable　to　the　vanity　of　mankind；　taking　up　the　subject　at　this　point；　he　would　then　very　clearly　and　shortly　explain　it。
  His　acquaintance　with　mathematics　was　very　limited。　　Many　years　since；　when　I　was　an　unsuccessful　candidate　for　a　professorship　of　mathematics；　I　applied　to　Dr。　W。　for　a　recommendation；　he　declined　it；　on　the　ground　of　its　not　being　his　pursuit。　　I　told　him　I　asked　it；　because　I　thought　it　would　have　weight；　to　which　he　replied；　that　it　ought　to　have　none　whatever。　　There　is　no　doubt　his　view　was　the　just　one。　　Yet　such　is　the　state　of　ignorance　which　exists　on　these　subjects；　that　I　have　several　times　heard　him　mentioned　as　one　of　the　greatest　mathematicians　of　the　age。　　＇This　of　course　could　only　have　happened　in　England。＇　But　in　this　as　in　all　other　points；　the　precision　with　which　he　comprehended　and　retained　all　he　had　ever　learned；　especially　of　the　elementary　applications　of　mathematics　to　physics；　was　such；　that　he　possessed　greater　command　over　those　subjects　than　many　of　far　more　extensive　knowledge。
  In　associating　with　Wollaston；　you　perceived　that　the　predominant　principle　was　to　avoid　error；　in　the　society　of　Davy；　you　saw　that　it　was　the　desire　to　see　and　make　known　truth。　　Wollaston　never　could　have　been　a　poet；　Davy　might　have　been　a　great　one。
  A　question　which　I　put；　successively；　to　each　of　these　distinguished　philosophers；　will　show　how　very　differently　a　subject　may　be　viewed　by　minds　even　of　the　highest　order。
  About　the　time　Mr。　Perkins　was　making　his　experiments　on　the　compression　of　water；　I　was　much　struck　with　the　mechanical　means　he　had　brought　to　bear　on　the　subject；　and　was　speculating　on　other　applications　of　it；　which　I　will　presently　mention。
  Meeting　Dr。　Wollaston　one　morning　in　the　shop　of　a　bookseller；　I　proposed　this　question：　　If　two　volumes　of　hydrogen　and　one　of　oxygen　are　mixed　together　in　a　vessel；　and　if　by　mechanical　pressure　they　can　be　so　condensed　as　to　become　of　the　same　specific　gravity　as　water；　will　the　gases　under　these　circumstances　unite　and　form　water？　　〃What　do　you　think　they　will　do？〃　　said　Dr。　W。　　I　replied；　that　I　should　rather　expect　they　would　unite。　　〃I　see　no　reason　to　suppose　it；〃　　said　he。　　I　then　inquired　whether　he　thought　the　experiment　worth　making。　　He　answered；　that　he　did　not；　for　that　he　should　think　it　would　certainly　not　succeed。
  A　few　days　after；　I　proposed　the　same　question　to　Sir　Humphry　Davy。　　He　at　once　said；　〃they　will　become　water；　of　course；〃　and　on　my　inquiring　whether　he　thought　the　experiment　worth　making；　he　observed　that　it　was　a　good　experiment；　but　one　which　it　was　hardly　necessary　to　make；　as　it　must　succeed。
  These　were　off…hand　answers；　which　it　might　perhaps　be　hardly　fair　to　have　recorded；　had　they　been　of　persons　of　less　eminent　talent：　　and　it　adds　to　the　curiosity　of　the　circumstance　to　mention；　that　I　believe　Dr。　Wollaston's　reason　for　supposing　no　union　would　take　place；　arose　from　the　nature　of　the　electrical　relations　of　the　two　gases　remaining　unchanged；　an　objection　which　did　not　weigh　with　the　philosopher　whose　discoveries　had　given　birth　to　it。
  ＇The　result　of　the　experiment　appeared；　and　still　appears　to　me；　to　be　of　the　highest　importance；　and　I　will　shortly　state　the　views　with　which　it　was　connected。　　The　next　great　discovery　in　chemistry　to　definite　proportions；　will　be　to　find　means　of　forming　all　the　simple　unions　of　one　atom　with　one；　with　two；　or　with　more　of　say　other　substance：　　and　it　occurred　to　me　that　the　gaseous　bodies　presented　the　fairest　chance　of　success；　and　that　if　wishing；　for　instance；　to　unite　four　atoms　of　one　substance　with　one　of　another；　we　could；　by　mechanical　means；　reduce　the　mixed　gases　to　the　same　specific　gravity　as　the　substance　would　possess　which　resulted　from　their　union；　then　either　that　such　union　would　actually　take　place；　or　the　particles　of　the　two　substances　would　be　most　favourably　situated　for　the　action　of　calori