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XLIX. A Letter from Dr. Hutton ; with Communications 

 from, the Marquis De Laplace. 



To Mr. Tilloch. 



Sir, — In the Philosophical Magazine of February last, you 

 were so obliging as to insert a note from me on the subject of 

 my Calculations on the Density of the Earth ; for I then ap- 

 prehended that the credit of that operation had been transferred 

 to others : and I scarcely need observe, that as honour is the 

 chief reward of scientific labours, it was natural that I should 

 feel some uneasiness on being unjustly deprived of what I con- 

 ceived my right. 



You also had the goodness at the same time to insert the copy 

 of a letter on the same subject, which I had addressed to the 

 Marquis De Laplace, under an idea that his Lordship had for- 

 gotten to acknowledge the receipt of that little communication. 

 In this apprehension, however, I am happy to find that I was 

 mistaken, as the delay arose, not from any neglect on his part, 

 but rather from his attention to the subject, in preparing a ])ror- 

 found and interesting paper on the earth's density, a copy of 

 which he has transmitted to me, with the following very kind 

 and obliging letter. 



*' To Dr. Hutton. 



"Paris, Sept. 11, 1820. 

 " Sir, — 1 hope you will have the goodness to accept my ex- 

 cuse for not replying sooner to the letter with which you ho- 

 noured me. I expected everyday that the Tracts I am printing 

 in the volumes of the Connoissance des Terns would give me an 

 opportunity of inserting what you seemed to wish. But as this 

 opportunity has not yet occurred, I have resolved to publish, for 

 the express purpose, a Memoir on the Density of the Earth, in 

 the volume of the Connoissance des Terns for 1823, which will 

 soon appear. I have the honour to send you a copy of this pa- 

 per. It is my wish that it may satisfy you; being very desirous 

 to prove to you how much I esteem your talents, and honour 

 your person. I thank you for the present you have been so 

 good as to send me of the collection of your Tracts. I have 

 been long acquainted with your profound researches, which 

 secure to you a distinguished rank among geometricians, and 

 which have long inspired me with a high estetm for you. the 

 expression of which 1 beg you will accept. 



" M. De LAPX.ACK." 

 Vol. 5(i. No. 27 1 . Nov. 1820. S s Although 



