Schenk's theory : the determination of sex / by Leopold Schenk. Authorized translation.

  • Leopold Schenk
Date:
1898
Catalogue details

Licence: Public Domain Mark

Credit: Schenk's theory : the determination of sex / by Leopold Schenk. Authorized translation. 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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    nitrogen. Nitrogen is excreted both by the urine and the fseces. The greater part is found in the urine, whilst, on the contrary, the quantity of nitro- gen excreted in the faeces amounts to more [? less] than I gramme per day. If, then, we determine the quantity in the urine alone, and add 0*94 gramme as a correction for the nitrogen excreted with the fseces, the resulting error will be un- important. The best and at present most usual method of determining the nitrogen is that of Kjeidahl. I generally use it in my analyses as one that can be conveniently carried out. For this purpose we place 5 cubic centi- metres of filtered urine in a long-necked flask, add about 3 decigrammes of yellow oxide of mercury and 10 cubic centimetres of chemically pure sulphuric acid. We then carefully warm the brownish - black mixture over the flame of a Bunsen burner until it has become colourless. We now allow it to cool. The mixture is now poured into an Erlenmayer flask containing three- quarters of a litre of water, is neutralised with 30 per cent, soda-lye and then 40 cubic centimetres of a 4 per cent, solution of ipotassium sulphide is added. The whole is next subjected to dis- tillation. Decinormal sulphuric acid contained in the receiver takes up the ammonia which