A handy method of determining the amount of carbonic acid in air / by William Mackie.

  • Mackie, William.
Date:
1905
Catalogue details

Licence: In copyright

Credit: A handy method of determining the amount of carbonic acid in air / by William Mackie. Source: Wellcome Collection.

Provider: This material has been provided by The Royal College of Surgeons of England. The original may be consulted at The Royal College of Surgeons of England.

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    A HANDY METHOD OF DETERMINING THE AMOUNT OF CARBONIC ACID IN AIR. By william MACKIE, M.A., M.D., D.P.H. (Aberdeen). Many years ago while making in the laboratory of the late Prof. Carnelley in Dundee, by Pettenkofer’s method, a series of Carbonic Acid determinations, in which turmeric paper was used as the indicator, I observed that the last few brown rings made on the paper as the solution approached neutralization showed a tendency to become decolorized in a relatively short space of time, the final ones being seen to vanish even as one looked at them. This at the time—and subsequent observation has confirmed the truth of the conclusion—was ascribed to the CO2 of the air rapidly neutralizing the solution of baryta, which getting more and more dilute as the solution of oxalic acid was gradually added, finally reached a degree of dilution that was all but instantly neutralized by the amount of CO2 present in an ordinary I atmosphere. Even then I came to the conclusion that the phenomenon 'depended on a principle which might probably be made the basis of I a rapid method of estimating the amount of CO2 in air generally, but iit is only recently that I have had time to adjust the details of the I method which I now propose. It will readily be understood that a long .'Series of e^eriments other than those of which the results arc now irecorded wose carried out before finality was reached on many points of tthe method. These need not be detailed here, though some of them uvill be alluded to as occasion arises. It may be stated that the method lhas been found to give results which approximate to the truth—at least ras tested by Pettenkofer’s method—much more closely than was at first 'anticipated. The special recommendations of the method are, easiness and rrapidity of execution, simplicity and inexpensiveness of apparatus, with •equal simplicity of the calculations necessary to obtain a definite rresult. Journ. of Hyg. v 14