440 



COMMERCIAL POULTRY RAISING 



eggs rubbed with salt were bad, and the same proportion of 

 those preserved by packing in bran, or covered with paraffin or 

 varnished with a solution of glycerin and salicylic acid. Of the 

 eggs sterilized by placing in boiling water for I2 to 15 seconds, 

 50 per cent were bad. One-half of those treated with a solution 

 of alum or put in a solution of salicylic acid were also bad. Forty 

 per cent of the eggs varnished with water glass, collodion or 

 shellac were spoiled. Twenty per cent of the eggs packed in peat 

 dust were unfit for use, the same percentage of those preserved in 

 wood ashes, or treated with a solution of boracic acid and water 



glass, or with a solu- 

 tion of permangan- 

 ate of potash, were 

 also bad. Some of 

 the eggs were var- 

 nished with vaseline ; 

 these were all good, 

 as were those pre- 

 served in limewater 

 or in a solution of 

 water glass. 



Of the three meth- 

 ods that were en- 

 tirely successful, the 

 water glass treat- 

 ment is to be recom- 

 mended. Covering eggs with vaseline requires too much time, and 

 the idea is not a particularly pleasant one. The limewater treat- 

 ment sometimes communicates an odor to the eggs. 



Water glass, or soluble glass, is the popular term for sodium 

 silicate or potassium silicate, the commercial article often being a 

 mixture of the two. The commercial product is generally used 

 for preserving eggs, if it is of a good grade, inasmuch as the 

 chemically pure article, which is used for medical and other pur- 

 poses, is very much more expensive. Inferior grades are likely 

 to be alkaline, which should not be used, as the alkali will 



(Courtesy Wisconsin Experiment Station) 

 Fig. 281 . — Preparing water glass for preserving eggs. 



