ANIMAL HEAT 525 



After death the body cools at first rapidly, then more slowly 

 (Fig. 144). But occasionally a post-mortem rise of temperature 

 may take place. In certain acute diseases (like tetanus) associated 

 with excessive muscular contraction this has been especially noticed ; 

 in bodies wasted by prolonged illness it does not occur. Nearly an 

 hour after death, in a case of tetanus, the temperature was found to 

 be 45*3, while before death it was 447 (Wunderlich). In dogs a 

 slight post-mortem rise may be demonstrated, especially when the 

 body is wrapped up ; but when an animal has been long under the 

 influence of anaesthetics, no indication whatever of the phenomenon 

 may be obtained. The explanation of post-mortem rise of tempera- 

 ture is to be found : (i) In the continued metabolism of the tissues 

 for some time after the heart has ceased to beat, for the cell dies 

 harder than the body. (2) In the diminished loss of heat, due to 

 the stoppage of the circulation. (3) Possibly to a small extent in 

 physical changes (rigor mortis, coagulation of blood) in which heat 

 is set free. 



PRACTICAL EXERCISES ON CHAPTERS VII. AND. VIII. 



i. Glycogen (i) Preparation. (a) Place in a mortar some fine 

 sand and a mixture of equal volumes of saturated solution of 

 mercuric chloride and Esbach's reagent.* Put one or two oysters 

 in the mortar, rub up thoroughly, and let the mass stand till (b) and 

 (c] have been done, stirring it occasionally. Then filter and pre- 

 cipitate the glycogen from the filtrate with alcohol. Filter again, 

 wash the precipitate on the filter with a little alcohol, dissolve it in 

 i or 2 c.c. of water, and test for glycogen as in (b). The mercuric 

 chloride and Esbach's reagent are added to precipitate the proteids, 

 which are more completely thrown down in this way than by the 

 methods used in (b) and (c) (Huizinga). 



(b] Cut an oyster into two or three pieces, throw it into boiling 

 water, and boil for a minute or two. Rub up in a mortar with clean 

 sand, and again boil. Filter. Precipitate any proteids which have 

 not been coagulated, by adding alternately a drop or two of hydro- 

 chloric acid and a few drops of potassio -mercuric iodide so long as 

 a precipitate is produced. Only a small quantity of these reagents 

 will be required, as the greater part of the proteids has been already 

 coagulated by boiling. Filter if any precipitate has formed. The 

 filtrate is opalescent. Precipitate the glycogen from the filtrate (after 

 concentration on the water-bath if it exceeds a few c.c. in bulk) by 

 the addition of four or five times its volume of alcohol. Filter off 

 the precipitate, wash it on the filter with alcohol, and dissolve it in a 

 little water. To some of the solution add a drop or two of iodine ; 

 a reddish-brown (port wine) colour is produced, which disappears on 

 heating, returns on cooling, is removed by an alkali, restored by an 

 acid. Add saliva to some of the glycogen solution, and put in a 

 bath at 40 C. In a few minutes reducing sugar (maltose) will be 

 found in it by Trommer's test (p. 23). 



* Esbach's reagent is a solution of 10 grm. picric acid and 20 grm 

 citric acid in a litre of water. 



