Experiments on the metabolism of matter and energy in the human body / By W.O. Atwater, PH.D., and F.G. Benedict, PH.D., with the cooperation of A.W. Smith, M.S., and A.P. Bryant, M.S.
- Wilbur Olin Atwater
- Date:
- 1899
Licence: Public Domain Mark
Credit: Experiments on the metabolism of matter and energy in the human body / By W.O. Atwater, PH.D., and F.G. Benedict, PH.D., with the cooperation of A.W. Smith, M.S., and A.P. Bryant, M.S. Source: Wellcome Collection.
Provider: This material has been provided by the Augustus C. Long Health Sciences Library at Columbia University and Columbia University Libraries/Information Services, through the Medical Heritage Library. The original may be consulted at the the Augustus C. Long Health Sciences Library at Columbia University and Columbia University.
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![shown by tbe sooty flames and odors. Au attempt was made to secure a wick free from carbon bj^ the use of asbestus, but owing to the poor capillarity of the latter a constant rate of combustion could not be maintained. Various modifications of the method by the use of asbestus were tried, but without success. Either the rate of combustion could not be regulated or the oxidation was not complete. The method of securing the complete combustion of ethyl alcohol, which proved most satisfactory and was afterwards used in the alcohol tests of the accuracy of the measurements of carbon dioxid, water, and heat in the calorimeter, was as follows: The essential feature of the flame was a central draft of air. To secure this an ordinary small kerosene lamp with an Argand burner and chimney was found very satisfactory; that is to say, the alcohol was used in this simple lamp in exactly the same way that kerosene would be burned. The flame of the burning alcohol was nonluminous, but it still remained to show conclusively that there was no trace of unoxidized material in the vapors from the burning alcohol. If the supply of oxygen is insufficient, several i)roducts are, at least theoret- ically, capable of being formed. Such products are carbon monoxid, aldehyde, acetic acid, and hydrocarbons. In order to test for these compounds, it is first necessary to free them from the carbon dioxid and water—that is, from the products of com- plete combustion of the burning alcohol. For this j)urpose the lamp in which the alcohol was burning was placed under an inverted funnel, the stem of which was sealed to a glass tube connected with a system of tubes and solutions for the removal of different combustion i>roducts from the air. A strong suction from a water pump maintained a cur- rent of air through the whole system, so that a large proportion, assumed to be nearly all, of the products of combustion were drawn in and through the apparatus along with some of the air from the room. The current thus passing in at the inverted funnel was first drawn through bottles containing a saturated solution of caustic potash, which sufficed for the removal of practically all the carbon dioxid and water, as well as volatile liquids formed from the incomplete combustion of the alcohol. Tests for such substances were subsequently made by another method. For the removal of the last traces of carbon dioxid, soda lime contained in U-tubes, was employed. A clear solution of barium liydroxid inserted in the system showed that the removal of carbon dioxid was conjplete. Gaseous hydro(;arbons and carbon monoxid that might have been formed by incomplet(i oxidation of the alcohol are practically insoluble in causti(^ ]>otash solution, and their presence in tlie air current freed from carbon dioxid is easily established by passing the air through a short combustion tube containing granulated cui)iic oxid heated to red- ness, and finally through a solution of barium hydroxid. In this way any incomifletely oxidized gas would be oxidized to carbon dioxid, which would produce a turbidity or precipitate in this latter solution.](https://iiif.wellcomecollection.org/image/b21229636_0014.jp2/full/800%2C/0/default.jpg)
