VOL. LI.] PHILOSOPHICAL TRANSACTIONS. 435 



XLIX. Montium quorundam prcealtorum, magna ligni fossilis copia quasi in- 

 farctoruTriy hrevis descriptio Sam. Christ, Hollmanni, Phil. Professoris Goet- 

 tingensis, et S. R. Sodalis. p. 506. 



In this paper it is stated that immense quantities of fossil wood are found in 

 the lofty mountains situated in the confines of Hesse and the principality of 

 Goettingen. 



Jj. Experiments in Electricity : in a Letter from Father Beccaria, Professor of 

 Experimental Philosophy at Turin, to Benj. Franklin, L L. D., F. R. S. p. 5 14. 

 To be read improved in the published works of Fa. Beccaria. 



Remarks on the preceding Paper. By Benj . Franklin, LL.D., F.R.S. p. 525. 



For the better understanding this paper, it is necessary to know that Father 

 Beccaria uses a large chain, suspended by silk lines, for the purpose of a prime 

 conductor; and that his machine for turning the glass globe is so contrived, as 

 that he can, on occasion, readily isolate it, i. e. place it on glass or wax, together 

 with the person that works it. When the communication is thus cut off be- 

 tween the earth and the chain, and also between the earth and the machine, 

 he observes that the globe being turned, both the chain and the machine show 

 signs of electricity ; and as these signs, when examined, appear to be different in 

 the chain and in the machine, and the globe having, as he supposes, drawn 

 from the machine part of its natural or common quantity of electricity, and 

 given it to the chain, he calls the electricity appearing in the chain, electricity 

 by excess; and the electricity appearing in the machine, electricity by defect; 

 which answer to our terms of positive and negative electricity, or electricity plus 

 and minus. And thus his expressions, electrifying by the chain, and electri- 

 fying by the machine, are to be understood, electrifying positively, and electri- 

 fying negatively. 



LJ. ^4n Uncommon Case of an Haemoptysis. By Eras. Darwin, M.D. p. 526. 



A gentleman residing near Litchfield, between 40 and 50 years of age, of a 

 pale and meagre habit, had been daily afflicted with violent head-aches for several 

 years; and, about 4 years before, after having taken a considerable quantity of 

 Peruvian bark, became suddenly paralytic. The use however of his right limbs 

 was so much restored as only to remain weaker than the other; when, on sud- 

 denly awaking from his sleep about 2 o'clock in the morning. May 7, 1759, he 

 spit up 4 or 5 02;. of florid blood. He immediately lost 12 or 14 oz. from the 

 arm, had elixir of vitriol given him, and in the evening had a clyster, and lost 

 blood again to about 10 oz. 



On the 8th, about the same hour, he again suddenly awaked, and spit about 



3 K 2 



