(see Lighting: Electric) and is no longer in use. Jablochkov made various other electrical inventions, but he died in poverty, having returned to Russia on the 19th of March 1894.
JABLONSKI, DANIEL ERNST (1660–1741), German theologian,
was born at Nassenhuben, near Danzig, on the 20th of
November 1660. His father was a minister of the Moravian
Church, who had taken the name of Peter Figulus on his baptism;
the son, however, preferred the Bohemian family name of
Jablonski. His maternal grandfather, Johann Amos Comenius
(d. 1670), was a bishop of the Moravian Church. Having studied
at Frankfort-on-the-Oder and at Oxford, Jablonski entered upon
his career as a preacher at Magdeburg in 1683, and then from
1686 to 1691 he was the head of the Moravian college at Lissa,
a position which had been filled by his grandfather. Still retaining
his connexion with the Moravians, he was appointed court
preacher at Königsberg in 1691 by the elector of Brandenburg,
Frederick III., and here, entering upon a career of great activity,
he soon became a person of influence in court circles. In 1693
he was transferred to Berlin as court preacher, and in 1699 he
was consecrated a bishop of the Moravian Church. At Berlin
Jablonski worked hard to bring about a union between the
followers of Luther and those of Calvin; the courts of Berlin,
Hanover, Brunswick and Gotha were interested in his scheme,
and his principal helper was the philosopher Leibnitz. His idea
appears to have been to form a general union between the
German, the English and the Swiss Protestants, and thus to
establish una eademque sancta catholica et apostolica eademque
evangelica et reformata ecclesia. For some years negotiations
were carried on with a view to attaining this end, but eventually
it was found impossible to surmount the many difficulties in the
way; Jablonski and Leibnitz, however, did not cease to believe
in the possibility of accomplishing their purpose. Jablonski’s
next plan was to reform the Church of Prussia by introducing
into it the episcopate, and also the liturgy of the English
Church, but here again he was unsuccessful. As a scholar
Jablonski brought out a Hebrew edition of the Old Testament,
and translated Bentley’s A Confutation of Atheism into Latin
(1696). He had some share in founding the Berlin Academy of
Sciences, of which he was president in 1733, and he received
a degree from the university of Oxford. He died on the 25th
of May 1741.
Jablonski’s son, Paul Ernst Jablonski (1693–1757), was professor of theology and philosophy at the university of Frankfort-on-the-Oder.
Editions of the letters which passed between Jablonski and Leibnitz, relative to the proposed union, were published at Leipzig in 1747 and at Dorpat in 1899.
JABORANDI, a name given in a generic manner in Brazil and
South America generally to a number of different plants, all
of which possess more or less marked sialogogue and sudorific
properties. In the year 1875 a drug was introduced under the
above name to the notice of medical men in France by Dr
Coutinho of Pernambuco, its botanical source being then unknown.
Pilocarpus pennatifolius, a member of the natural
order Rutaceae, the plant from which it is obtained, is a slightly
branched shrub about 10 ft. high, growing in Paraguay and the
eastern provinces of Brazil. The leaves, which are placed
alternately on the stem, are often 112 ft. long, and consist of from
two to five pairs of opposite leaflets, the terminal one having a
longer pedicel than the others. The leaflets are oval, lanceolate,
entire and obtuse, with the apex often slightly indented, from
3 to 4 in. long and 1 to 112 in. broad in the middle. When held
up to the light they may be observed to have scattered all over
them numerous pellucid dots or receptacles of secretion immersed
in the substance of the leaf. The leaves in size and texture
bear some resemblance to those of the cherry-laurel (Prunus
laurocerasus), but are less polished on the upper surface. The
flowers, which are produced in spring and early summer, are
borne on a raceme, 6 or 8 in. long, and the fruit consists of five
carpels, of which not more than two or three usually arrive at
maturity. The leaves are the part of the plant usually imported,
although occasionally the stems and roots are attached to them.
The active principle for which the name pilocarpine, suggested by
Holmes, was ultimately adopted, was discovered almost simultaneously
by Hardy in France and Gerrard in England, but was first
obtained in a pure state by Petit of Paris. It is a liquid alkaloid,
slightly soluble in water, and very soluble in alcohol, ether and
chloroform. It strongly rotates the plane of polarization to the
right, and forms crystalline salts of which the nitrate is that
chiefly used in medicine. The nitrate and phosphate are
insoluble in ether, chloroform and benzol, while the hydrochlorate
and hydrobromate dissolve both in these menstrua and
in water and alcohol; the sulphate and acetate being deliquescent
are not employed medicinally. The formula of the alkaloid
is C11H16N2O2.
Certain other alkaloids are present in the leaves. They have been named jaborine, jaboridine and pilocarpidine. The first of these is the most important and constant. It is possibly derived from pilocarpine, and has the formula C22H32N4O4. Jaborine resembles atropine pharmacologically, and is therefore antagonistic to pilocarpine. The various preparations of jaborandi leaves are therefore undesirable for therapeutic purposes, and only the nitrate of pilocarpine itself should be used. This is a white crystalline powder, soluble in the ratio of about one part in ten of cold water. The dose is 120–12 grain by the mouth, and up to one-third of a grain hypodermically, in which fashion it is usually given.
 |
| Jaborandi—a, leaf (reduced); b, leaflet (natural size); c, flower; d, fruit (natural size). |
The action of this powerful alkaloid closely resembles that of physostigmine, but whereas the latter is specially active in influencing the heart, the eye and the spinal cord, pilocarpine exerts its greatest power on the secretions. It has no external action. When taken by the mouth the drug is rapidly absorbed and stimulates the secretions of the entire alimentary tract, though not of the liver. The action on the salivary glands is the most marked and the best understood. The great flow of saliva is due to an action of the drug, after absorption, on the terminations of the chorda tympani, sympathetic and other nerves of salivary secretion. The gland cells themselves are unaffected. The nerves are so violently excited that direct stimulation of them by electricity adds nothing to the rate of salivary flow. The action is antagonized by atropine, which paralyses the nerve terminals. About 1100th of a grain of atropine
