BLACK 109 Dr. Black's theory has been adopted by every modern chemist, yet great differences have existed with respect to the quantity of heat thus absorbed. This doctrine was immediately applied by its author to the explanation of a vast number of natural phenomena, and in his experimental investigations he was greatly assisted by his two celebrated pupils, Dr. Irvine and Mr. Watt; the latter of these gentlemen afterwards adding great improvements to the steam-engine of Bolton, from the circumstance of his un- derstanding so well the theory of that powerful agent. This theory was explained in his lectures every year to a vast concourse of students from all parts of Europe; yet the criminal negligence of the author in not favouring the world with a printed account of his discovery, has caused the credit of it to be assigned to various persons, whose ideas on the subject were obtained from him alone. Laplace, in his Investigations concerning Heat, published many years after, obviously borrowed largely from Dr. Black, and indeed exbibited little more than the experi- ments which he had suggested. He, however, never mentions Dr. Blaek at all; every thing in his dissertation assumes the air of originality; he rather appears to have taken some pains to prevent the opinions and discoveries of our celebrated chemist from being known or attended to by his countrymen. The observations of Dr. Crawford on the capacities of different bodies for heat, were also borrowed in a great measure fron Dr. Black, who first pointed out the proper, method of investigating that subject. The most ex traordinary proceeding, however, was that of De Luc, which exhibits an audacity unparelleled in the annals of scientific or literary plagiarism. He expressed to Dr. Black his unbounded admiration of his beautiful theory of latent heat, and offered with much zeal to be- come his editor. Averse to trouble and exertion, he after much difficulty consented to furnish De Luc with the ne- cessary materials to prepare the work for the public eye.
