122 On the Geology of Northumberland. 
effectually to have corroborated those already attempted; and 
which pledge I had the sincerest intention of .redeeming, had } 
not found an absolute necessity for directing all the power of 
my facuities into other less important but more profitable chan- 
nels. But at all events, as there appears to be a disposition evinced 
by Mr. Tatum to pursue these inguiries, I eonsider it my duty 
to point out to him what has been already done—not so much 
under the ideaof my experiments being of sufficient consequence to 
supersede his investigations, as of their being perhaps worthy to 
be considered as a land-mark by which he may avoid some su- 
perfluous trouble; and be induced, if he thinks proper, to take 
some of the most prominent of mine as points whence to set 
forward on a fresh career. I have not sufficient vanity to be- 
lieve mine of any great consequence ; but as his pursuits in the 
same path appear so nearly allied to those which so greatly en- 
gaged my attention, I trust he will excuse my officiousness for 
thus eagerly endeavouring to arrest his further progress till he 
has condescended to give them a serious perusal. If the greatest 
assiduity and accuracy may entitle them to notice, 1 feel con- 
scious no pains were spared in these particulars; I only lament the 
occurrence of those untoward events which induced me to relin- 
quish their further progress, and I shall experience no small gra- 
tification if they shall ultimately be found of sufficient conse- 
quence to facilitate and shorten the labours of others wishing to 
analyse and throw light upon similar subjects. 
A friend of mine has lately presented me with two specimens_ 
of calcareous matter, taken from the bladders of two of his 
horses after they had died from disease,—one weighing nearly 
ten pounds, in an irregular form,—the other weighing about ter 
pounds and a quarter, of a conic form. As soon as I can pos= 
sibly find time for their minute examination, it is my intention ta 
send you the particulars. 
I am, sir, 
Your most obedient servant, 
Ipswich, Aug. 6, 1817. v J. Acron, 
XIX. On the Geology of Northumberland. By N.J.Wincx, 
Esq. 
To Mr. Tulloch. 
Sir, — In a memoir on the geology of Northumberland, Dur- 
ham, &c. published in the fourth volume of the Annals of Phi- 
losophy, Dr. Thomson makes the following observation :— In 
the preceding rapid sketch I have taken no notice of small 
patches of the newest floetz-trap which occur towards the north- 
east 
