226 Linncean Society. 



tion, and that the time of the heart's systole is nearly tlie half of the 

 whole time of a pulsation ; and upon the formula given by Dr. Young 

 in the Philosophical Transactions for 1S08, for estimating the friction 

 of fluids moving in pipes : in the application of that formula the 

 mean dimensions of the circulating vessels are assumed as in Dr. 

 Young's Croonian Lecture, published in J 809. He thus arrives at 

 the conclusion, — that the motion of the blood becomes uniform at the 

 26th division of the arteries, reckoned from the aorta ; and that at 

 this point, the pressure, as measured by the corresponding heights, 

 is reduced from 90 to 80 inches. 



As there are cases on record of universal venous pulsation, the 

 author pursues the inquiry into the mechanical conditions, which tend 

 to favour the production of this effect : and also applies the results 

 of the analysis to the explanation of the throbbing, or extension of 

 the pulse into parts where, in a state of health, it is not met with, 

 •which accompanies phlegmonous inflammation. 



" On the mutual action of sulphuric acid and alcohol, and on the 

 nature of the process by which ether is formed," by Henry Hennel, 

 Esq. Communicated jjy W. T. Brande, F.R.S. 



The most abundant product resulting from the mutual action of 

 sulphuric acid and alcohol, without the application of heat, is the 

 sulphovinic acid : but on distillation, this peculiar product disap- 

 pears, and ether is formed : and it becomes a question what part the 

 sulphovinic acid plays in this process. In opposition to the assertion 

 of Messrs. Dumas and Boullay, — that this acid is not concerned in the 

 production of ether, the author contends, that whenever ether is formed, 

 it is in consequence of the decomposition of the sulphovinic acid. He 

 obtained ether from this latter fluid by distillation, when neither sul- 

 phuric acid nor alcohol was present. But if a certain quantity of 

 water has been previously added, the sulphovinic acid is resolved into 

 alcohol and sulphuric acid, and no ether is obtained : whereas, during 

 the distillation of ether in the ordinary way, the sulphovinic acid is 

 reconverted more or les.s entirely into sulphuric acid. Hence he in- 

 fers, that the formation of the sulphovinic acid is a necessary and in- 

 termediate step to the production of ether from alcohol and sulphu- 

 ric acid. As ether may be formed from alcohol, by the interme- 

 dium of sulphuric acid, so, by the same intermedium, may alcohol be 

 obtained from ether, sulphuric acid being formed in either case, 

 according to the mode of combination of the hydrocarbonous base. 

 This theory is also illustrated by the employment of olefiant gas as 

 the hydrocarbonous base ; for, by combining this gas with sulphuric 

 acid, we may form sulphovinic acid, from which we may obtain at 

 pleasure, by varying the circumstances of the decomposition, either 

 alcohol or ether. 



LINNiEAN SOCIETY. 



Nov. 1 8. — Read Notices of several Land and Fresh- water Shells 

 new to Great Britain, with occasional Observations, by J. G. Jef- 

 freys, Esq. 



Dec. 



