# Dictionary of National Biography, 1885-1900/Jeffreys, Julius

​JEFFREYS, JULIUS (1801–1877), inventor of the respirator and medical writer, fourth son of R. Jeffreys, rector of Throcking, Hertfordshire, was born at Hall Place, Kent, in 1801. He studied medicine at Edinburgh and London, and in 1822, at the early age of twenty-one, he wrote a tract ‘On the Comparative Forces of the Extensor and Flexor Muscles connected with the Joints,’ in which he ventured to controvert some current views. The work met with the approbation of Abernethy and other distinguished medical men. In the same year Jeffreys obtained an appointment on the medical establishment of Bengal, and while in India he made a series of meteorological observations which led him to recommend the formation of hill stations as health resorts. He indicated Simla, where there was then only a single house, as a suitable locality. After two years' service he was made staff-surgeon at Cawnpore, and he was very active in introducing various chemical manufactures into India. He returned ​to England in 1835, and in the following year, in order to relieve a widowed sister, Mrs. Nicol, who was suffering from a pulmonary attack, he invented the respirator, for which he obtained a patent on 23 Jan. Two other patents embodying various improvements were granted to him in 1844 and 1850 respectively. The appliance consists of a series of exceedingly thin perforated metallic diaphragms—rods, wires, or tubes were afterwards found to answer equally well—fixed in a suitable frame and applied over the mouth. The heat of the breath in passing out through the apparatus is communicated to the metallic diaphragms, and this heat is in turn transferred to the air inhaled. The respirator was very well received by the medical profession, Dr. Arnott mentioning it in a lecture at the Royal Institution in March 1836. It has now, however, somewhat fallen into disuse. Jeffreys subsequently devoted considerable attention to diseases of the respiratory organs, with special reference to this apparatus, embodying his views in the following works: ‘The Construction and Use of the Respirator,’ 1836; ‘Statics of the Chest,’ 1843; ‘The Atmospheric Treatment of the Chest,’ 1845; and ‘Remarks on Climate and Affections of the Throat and Lungs,’ 1849. In 1858 he published a small work on ‘The British Army in India; its Preservation by Appropriate Clothing,’ &c., which contained valuable suggestions.
He was elected a fellow of the Royal Society in 1840, and in the same year he communicated a paper to the ‘Proceedings’ on the solubility of silica by steam, which is also the subject of a paper read by him before the British Association in 1869.
In addition to his purely scientific investigations he was occupied with various inventions for heating and warming, propelling ships, lowering ships' boats, &c., for some of which he obtained patents in 1838 and 1844.
He was elected a member of the Medical and Chirurgical Society in 1838, and he became a fellow of the Geological Society in 1846. He died at Richmond, 13 May 1877.
[Lieutenant-colonel E. Jeffreys's A Confutative Biographical Notice of Julius Jeffreys, with full Account of his Patents, 1855; Proceedings of the Medical and Chirurgical Society, 1880, viii. 294.]
R. B. P.