The effects of pneumonia and of postmortem changes on the percentage of water in the brain of the albino rat / Helen Dean King.

  • King, Helen Dean, 1869-1955.
Date:
1911
Catalogue details

Licence: In copyright

Credit: The effects of pneumonia and of postmortem changes on the percentage of water in the brain of the albino rat / Helen Dean King. 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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    known, but this difficulty has been met in a manner which will be described later. When the 22 males were grouped, it was observed that five of them had been found dead; the records for these animals were placed in a series by themselves. In four of the other animals the disease had made little progress; these rats were also grouped by themselves.. The remaining 13 males belonged to the group of animals designated as ‘seriously affected,’ and were therefore classed together. It seemed desirable, in the first instance, to know whether the percentage of water in the brains of the (4) lightly affected ani- mals was different from that in the brains of the (13) more se- riously affected. A direct comparison between the two groups does not give this information because the animals are not of the same size, and consequently probably not of the same age. It is important, therefore, to learn whether in the group consisting of the 13 seriously affected animals those which were longer (larger) were also probably older. To test this point the 13 rec- ords were arranged in the order of the increasing body length in subgroups of 4, 4 and 5. Table 1 gives the average body length in mm., and the average percentage of water for the three sub- groups named. TABLE 1 Males NUMBER OF CASES AVERAGE BODY LENGTH IN MM. AVERAGE PERCENTAGE OF WATER IN BRAIN 4 173 77.92 4 195 77.64 5 209 77.58 As will be seen from an examination of this table, increasing body length gives a decrease in the average percentage of the water in the brain. In general then, the longer animals are older animals, as we should expect, for with advancing age would go an increase in the body length and a decrease in the percentage of water in the brain.