t i57 3 



XXIV. Some Account of the Life of the late Br. Josefm 



Black. 



L HIS eminent chemift was born at Bourdeaux,' in France, 

 in the year 1728. His parents were both natives of Great 

 Britain, and at an early age he was brought over to this 

 country, and educated for the medical profeffion at the uni- 

 verfity of Glafgow. Dr. Cullen being at that time lecturer 

 of chemiitry, Black became one of his favourite pupils, was 

 allowed the free ui'e of his laboratory, and atfifted him in his 

 experiments; by which means he acquired a decided tafte 

 for this branch of natural philofophy. In 1754 he took the 

 degree of doctor of phytic in the univerfity of Edinburgh, 

 wfiere he had ftudied for fomc time; and the choice which 

 he made in regard to the fubject: of his inaugural diflertation 

 gave a proof of his attachment to chemical purfuits. Tt was 

 De humor c acido a cibls or to et magnejla alba. The principles 

 of the doctrine which he brought forward in this thefis 

 lie afterwards fully explained in a paper read the next year 

 before a fociety in Edinburgh, and publifhed in the fecond 

 volume of E/Tays Phy/ical and Literary, 1 756; containing 

 experiments on magncfia alba, quick-lime, and alkaline fub- 

 ftances. In this paper, by an ingenious and philofophical 

 feries of researches, he evidently proved the exiftence of an 

 aerial fluid, which he called fixed air, the prefence of which 

 gave mildnefs, and its abfence caufticity, to alkalies and cal- 

 careous earths. This noble difcovery certainly paved the wav 

 to all that important knowledge refpecling aerial bodies 

 which has done fo much honour to the names of a Caven- 

 difh, a Pricftley, and a Lavoifier, and which have made che- 

 mical philofophy affirm e an entirely new form. 



In the year 1756, on the removal of Dr. Cullen to Edin- 

 burgh, Dr. Black became profeflbr of medicine and lecturer 

 on chemiftry in the univerfity of Glafgow. Next year he 

 enriched the fciertce of chcmiltry with the curious doctrine 

 of latent heat, in which he explained, in what has been hi- 

 therto reckoned a clear and fatisfactory manner, the connec- 

 tion of heat with fluidity, the phenomena of freezing and 

 boiling, and the manner in which they affect: the thermo- 

 meter. Thefe difcoveries, the refult of great natural fagacitv 

 and experimental ikill, certainly laid the foundation of all 

 thole important facts relating to this part of chemiftry which 

 were afterwards brought to light by feveral of the moft emi- 

 nent philofophers of the prefent period, and would alone be 

 fufBcient to give celebrity to the name of Black. His re- 

 putation, 



