Hydraulic cement in N. York State, xxxvi, 45. ---- limestones of N. York, xxxix, 96; xlvi, 29. ---- ---- in the Appalachian chain, xxxvii, 381. ---- ----, magnesian character of, xxxvii, 381. ---- machine, new, ii, 345. ---- ram, new, iii, 381. ---- volcano, xxii, 358. Hydriodic acid, preparation of, xvi, 383; xlvii, 192. Hydroboracite, analysis of, xxviii, 394. Hydrobromic acid, xlvii, 192. Hydro-carbo-sulphuric acid, how prepared, vii, 187. Hydrochloric acid, notice of experiments with reference to, _Macaire_ and _De la Rive_, xi, 393. ---- ----, mode of preparing pure, from muriatic acid of commerce, _R. Hare_, xxxix, 371. ---- ----, fumigation with, at Plattsburgh, in 1819, viii, 200. ---- ----, condensation of, _M. Faraday_, vii, 357. Hydrocyanic acid, _F. Magendie_ on, ii, 81. ---- ----, memoir on, _B. L. Oliver_, iii, 182. ---- ----, ----, _Orfila_, xviii, 157. ---- ----, effect of muriatic and sulphuric acids on, xviii, 146. ---- ----, apparatus for the evolution of, _R. Hare_, xxix, 244.^f ---- ----, extraordinary production of, _A. A. Hayes_, xviii, 201. ---- ----, preservation of, xvi, 260. ---- ----, cases in which administered, ii, 83; iii, 187. ---- ----, efficacy in asthma, vi, 366. ---- ----, effects on a horse, xii, 385. ---- ----, effects of, on vegetation, x, 190. ---- ----, chlorine, an antidote for, xvii, 174; xxi, 157. Hydrogen, combustion of, under pressure, xxii, 352. ----, ----, in water, being a new application of Hare's blowpipe, v, 347. ----, mixed with oxygen, effect of breathing, viii, 375. ----, a new carburetted, xxx, 180. ----, gas apparatus, vii, 392. ----, self regulating reservoir for, _R. Hare_, xi, 140.^f ----, peroxyd of, action of, xvii, 34. ----, and chlorine, iii, 341. Hydromagnesite of Hoboken, _Wachtmeister_, analysis of, xviii, 167. Hydrometers, opinion on, _R. Hare_, xi, 115. Hydrophobia, remarks on, ii, 359; iv, 385; v, 177; xvii, 204. ----, singular case of, xvii, 205. ----, account of cases of deaths by, xxiii, 143. ----, cured, x, 385. ----, ----, by means of mercurial ointment, xix, 204. ----, ----, by Huaco, an Indian remedy, _W. R. Johnson_, xxiv, 279. Hydrosilicite, xv, 388. Hydrostatic balance, xix, 185. ----, press, xix, 185. Hydrous anthophyllite of N. York, _T. Thomson_, xix, 359. Hydroxanthic acid, vii, 376. Hygrometer, Daniell's, remarks on, _E. Loomis_, xlvii, 19; xlix, 277. ----, portable, _A. A. Hayes_, xvii, 351.^f Hygrometric Register at Western Reserve College, _E. Loomis_, Sept.-Nov. 1838, xxxvi, 166; --1838-1840, xli, 315; --1841-44 xlix, 271. ---- ----, at Hudson, Ohio, compared with those at Greenwich, _E. Loomis_, xlix, 276. ---- observations, mean of, at Malvern, in Worcestershire, xxxviii, 102. ---- ----, at Matanzas, _A. Mallory_, xxxi, 287. ---- ----, at New Orleans, _Barton_, xxxi, 400. ----, see farther under _Meteorology_.