166

ELEMENTS OF MATERIA MEDICA.

Conia agrees with ammonia in evolving a vapour which reddensturmeric paper, and forms white fumes (hydrochlorate of conia) withhydrochloric acid gas.

Composition. —Ammonia is composed of hydrogen and nitrogen, inthe following proportions :—■

Eq. Eq. Wt. Per Cent. A. Berthollet. Vol. Sp. Gr.

Nitrogen .

. i.

. 14 .

. . 82-35 .

. 81-13

Nitrogen gas . . .

Hydrogen .

. 3 .

. . 3 .

. . 17-65 .

. 18-87

Hydrogen gas . .

. 3 . . .

. . . 0-20833

Ammonia .

. 1 .

. 17 .

. 100-00 .

. 100-00

Ammoniacal gas .

. 2 . . .

. . . 0-59027

Constituents.

Eq. Vol.

il

1 eq.Hydr.

= 1

1 eq.Hydr.

= 1

1 eq.Hydr.

= 1

Amm

The annexed diagram illustrates the vo-lumes of the constituents of the gas, andtheir degree of condensation when in com-bination to form ammoniacal gas.

Physiological Effects. — (a.) On vege-tables. — Ammoniacal gas is destructive toplants, and changes their green colour tobrown (Decandolle, Physiol. Veg., p. 1344).

{b.) On animals. —If an animal be immersed in this gas, spasm of theglottis is immediately brought on, and death results from asphyxia.Nysten ( Reciterches , p. 140) injected some of this gas into the veins of adog : the animal cried out, respiration became difficult, and death soontook place. Neither gas nor visible lesion was observed in the heart,the two ventricles of which contained liquid blood. In another experi-ment he threw' ammoniacal gas into the pleura of a dog : cries, evacuationof urine, and vomiting, immediately followed; soon afterwards convul-sions came on, and continued for several hours ; ultimately they ceased,and recovery took place.

In almost all cases of poisoning in animals, by ammonia, or its car-bonate, convulsions are observed, apparently shewing that these sub-stances act on the spinal marrow.

(c.) On man. —Ammonia is a powerful local irritant. This is provedby its pungent odour, and its acrid and hot taste; by its irritating theeyes ; and, wdien applied for a sufficient length of time to the skin, by itscausing vesication. If an attempt be made to inhale it in the pure form,spasm of the glottis comes on : wdien diluted w r ith atmospheric air, itirritates the bronchial tubes and larynx, and, unless the quantity be verysmall, brings on inflammation of the lining membrane. Its powerfulaction on the nervous system is best seen in cases of syncope (see AquaAmmonia .)

Uses. —Ammoniacal gas is rarely employed in medicine. M. Bourguetde Beziers used it with success in the case of a child affected with croup,to provoke the expulsion of the false membrane.

Antidote. —In case of the accidental inhalation of strong ammoniacalvapour, the patient should immediately inspire the vapour of acetic orhydrochloric acid. If bronchial inflammation supervene, of course it isto be treated in the usual way.

A’qua Ammo'nia.— Water of Ammo'nia.

History and Synonymes. —The Liquor ammonia of the London Phar-macopoeia is, more properly as I conceive, denominated aqua ammonia