134 British Association for the Advancement of Science. 
body.—Dr. Blakiston read a paper on the sounds produced in 
respiration and on the voice.—Dr. G. Bird communicated obser- 
vations on poisoning by the vapors of burning charcoal. T'wo 
opinions prevail on the mode in which this gas produces death. 
1. That the gas acts negatively. 2. That the gas when respired, 
exerts a specific poisonous action on the nervous system. Dr. 
adopts the latter opinion.—Dr. Inglis read a paper, of which this 
was the summary :—1. Small pox is decidedly on the increase, 
and during each successive epidemic there is an increase of vari- 
olous patients from among those who were vaccinated in infancy. 
2. The vaccine virus is as effectual now as it ever was, but re- 
vaccination is necessary after a period of years, as yet unknown. 
3. The same cause which produces small pox during a variolous 
epidemic in the unvaccinated, may and does give rise to chicken 
pox in the vaccinated. 4. There is every reason to believe that 
cow pox had its origin in variola.—Mr. J, B. Estlin read a paper, 
to show, that the powers of the new virus diminish in intensity 
as successive vaccinations increased its distance from the cow.— 
Dr. R. D. Thomson, read a paper on alkaline indigestion, and 
gave the results of an extensive examination of patients laboring 
under this disease.—Mr. Hodgson read a paper on the red appear- 
ance on the internal coat of arteries, which he stated did not de- 
pend on inflammation in every instance, and from which it should 
be carefully distinguished.—Mr. C. 'T’. Coathupe gave the results 
of a series of experiments on respiration. (See this Journal, Vol. 
xxxvii, p. 367.)—Dr. Costello presented a report of ten cases of 
calculus treated by lithotrity——Mr. Nasmyth read a paper on the — 
microscopic structure of the teeth, in which he treated also of 
the covering of the enamel and of the organization of the pulp. 
He subsequently read a paper on the structure of the Epithelium, 
(a layer of substance destitute of vessels, covering the vascular 
surface of mucous membranes,) which he described as being. 
composed of cells.—Dr. L. Giiterbock exhibited several instru-_ 
ments made from ivory, softened by the removal of the earthy — 
matter by the action of dilute acid. He stated that the first 
idea of the preparation is contained in an English work published 
some time ago, entitled “ Useful Arts and Inventions.” 
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