Natural History. 181 
edge, and precipitated into the river Champlain, overwhelming in 
its ~progress barns, houses, trees, Gc. The river was dammed up 
for a distance of twenty-six arpents in an instant with an awful 
sound, and a dense vapour, as of pitch and sulphur. Various 
causes have been assigned for this phenomenon, of which the most 
probable, is the insinuation of water between the strata.—Phal. 
Mag. \xii. 470. 
Al. Existence of Free Muriatic Acid in the Stomach.—'The fol- 
lowing are the proofs of the existence of free muriatic acid which 
Dr. Prout has laid before the Royal Society. The contents of a 
stomach having been digested in distilled water, the solution ob- 
tained was divided into four equal parts. One of these evaporated 
to dryness, burnt and examined in the usual way, gave the quantity 
of muriatic acid in combination with fixed bases. A second being 
previously saturated with an alkali, was treated in a similar way, 
and gave the whole quantity of muriatic acid in the stomach, A 
third carefully neutralized with a known solution of alkali, gave the 
quantity of free acid. The fourth was reserved for any required 
experiment. In this way Dr. Prout ascertained that the unsatu- 
rated muriatic acid in the stomach was always considerable, and in 
one case twenty ounces of a fluid from a very deranged stomach, 
afforded him above half a drachm of muriatic acid of specific gra- 
vity 1.160. 
(12. Use of Sulphate of Copper in Croup. —Dr. H. Hoffman re- 
commends the sulphate of copper as an excellent remedy in croup, 
especially after blood-letting. In slight cases he begins with 
giving from a quarter to half a grain every two hours ; in those 
cases, however, where there is also laryngites, or bronchites, three, 
four, or more grains are administered, so as to excite instant 
vomiting ; by so doing, the Dr. thinks that not only is the lymph 
expelled from the trachea, but also that the further secretion of it 
is prevented, so that the patient is very much relieved, and soon 
‘cured. After copious vomiting has been produced, the medicine is 
to be given in small doses, in conjunction with digitalis. In sup- 
‘port of the utility of the above practice, Dr, H. affirms that he has 
employed it with the greatest success during a period of ten years, 
‘in a great number of children affected with croup, without ever 
having lost a patient in that time, notwithstanding the disease was 
often at its height when he was first called in. —Med. Rep. N.S. 1. 85. 
13. On Sand-drigs or Fulgorites, by MM. Viedler and Hagen,.— 
The ensuing observations have been selected from the account given 
‘in the Bib. Universelle, respecting these naturat sand-tubes, by 
MM. Fiedler and Hagen, ‘The latter person was particularly well 
circumstanced in ascertaining the cause of their formation, The 
