CHEMICAL SCIENCE. 187 



induced in it a series of changes, which gave rise to the excessive heat 

 and other peculiarities of that class of diseases. At the present time, 

 this doctrine, modified by the discoveries of Liebig and other chemists, 

 has been adopted by most physicians, and forms the basis of the classifi- 

 cation of disease framed by Dr. Farr, and used by the registrar-gene- 

 ral. It thus supposes living germs to exist in the atmosphere, which, 

 when introduced into the body, give rise to a specific and regular series 

 of morbid actions, pursuing a definite course in a definite time, as. in 

 small-pox, those germs being disclosed and multiplied, and producing 

 others capable of reproducing in other bodies the same succession of 

 changes. Other pathologists have supposed that the atmospheric poison 

 acts on the blood chemically, by giving rise to what may be termed 

 catalytic actions ; while the author is disposed to believe, from what he 

 saw during the cholera epidemic in Newcastle, in 1853, that some of 

 these volatile organic matters in the atmosphere are capable of acting 

 on the human body as direct poisons ; and that this inanimate, volatile, 

 poisonous matter also furnishes nutrition to the organic germs suspend- 

 ed in the air. After these preliminary remarks, he proceeded to refer 

 briefly to a number of scattered facts, which seemed to him to indicate 

 the existence of a great principle, which might hereafter be found ap- 

 j^icable to the prevention or mitigation of epidemic diseases, by the 

 direct use of substances capable of arresting the process of morbific fer- 

 mentation. He mentioned the following facts as converging to this 



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conclusion : 1. Antiseptic substances, ranging from simple, innocuous 

 matters, such as sugar, up to the powerful metallic poisons, such as cor- 

 rosive sublimate, and forming a very numeious and diversified group, 

 have been long known to be capable of arresting the putrefaction of 

 animal and vegetable structures. 2. The same substances prevent the 

 formation of fungi, as is seen in the use of solutions of metallic salts in 

 taxidermy, in the prevention of dry-rot, etc. 3. Many of those agents are 

 also known to arrest at once the process of fermentation, as, for in- 

 stance, sulphurous acid ; and Eini and other chemists have observed under 

 the microscope the rapid stoppage of the vitality of the yeast-plant when 

 a solution of arsenious acid was added to the fermenting liquor. 4. The 

 formation of the fungus in and on the plant, which causes the vine dis- 

 ease, is prevented by applying sulphur to the affected vines. 5. In 

 Cornwall, it is believed that the arsenical fumes from the tin-calcining 



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furnaces exercised an influence over the potato-plants in the neighbor- 

 hood, which preserved them from the disease then affecting other parts 

 of the same county. [A statement to this effect, signed by Capt. 

 Charles Thomas, sen., of Dolwath, and sixteen cottagers was here 

 read.] 6. It has been found, that when a species of fermentation has 

 taken place in the human stomach, resulting in the development in 

 large quantities of a minute organism (the sarcina ventri&uli), this mor- 

 bid action can be controlled and stopped by the direct anti-zymotic in- 

 fluence of certain salts, such as sulphate of soda, in doses perfectly 

 compatible with the patient's safety. 7. In different parts of the world, 

 among different races, a belief has long existed that certain antiseptic 

 substances, of which arsenic may be taken as the type, are capable of 

 acting as antidotes or preservative and curative agencies against atmos- 

 pheric and other poisons ; and in some cases that popular belief has 

 proved to be well-founded. The experience of the multitude discov- 



