"Your happiness on the contrary is quite secure because you place it entirely in making others happy and doing those things to the utmost of your power which you can afterwards reflect upon with satisfaction. I must own your letter had that effect upon me that it made me apply to my work with double eagerness and alacrity with the hopes of being some time what you are at present."

“Others in the pursuits after happiness or pleasure must commonly seek those sources of it which they cannot enjoy without some inconvenience to the rest of their fellow creatures; hence they have their imaginary happiness so much soured by Envy, Jealousy, or self-disapprobation that they find themselves dissappointed.”

“In the early part of my chymical studies, the author whose works made the most agreeable impression on my mind was Markgraaf of Berlin; he contrived and executed his experiments with so much chymical skill that they were uncommonly instructive and satisfactory; and he described them with so much modesty and simplicity, avoiding entirely the parade of erudition and self-importance, with which many other authors encumber their works, that I was quite charmed... and said to Dr. Cullen I would rather be the author of Markgraaf's Essays than of all the Chymical works in the library. The celebrated Reaumur's method of writing appeared to me also uncommonly pleasing. After 3 years spent with Dr. Cullen, I came to Edinburgh to finish my education in medicine. Here I attended the lectures of Dr. Munro, senr. and the other medical Professors, until the summer of the year 1754, when I received the degree of Doctor of Medicine, and printed my inaugural Dissertation De Humere Acido a Cibis Orto et Magnesia Alba.”

“When I am well instructed in a method of Practice here, a very short time of London will be sufficient; for then I need only observe the different manner of doing the same thing there, which I shall soon be master of.”