PRESERVING EGGS 



Of twenty methods of preserving eggs tested in Germany, the 

 three which proved the most effective were coating the eggs with 

 vaseline, preserving them in lime water, and preserving them in 

 water-glass. The conclusion was reached that the last was prefer- 

 able, because varnishing the eggs with vaseline takes considerable 

 time and treating them with the lime water may give them a dis- 

 agreeable taste. These drawbacks are not to be found with eggs 

 preserved in water-glass, which unquestionably is the best pre- 

 servative yet discovered. The most difficult point probably in the 

 use of water-glass for preserving eggs is its tendency to vary 

 in quality. As a matter of fact there are two or three kinds of 

 water-glass, and in addition to the fact that the buyer does not al- 

 ways have a distinct idea as to what he wants, the local druggist 

 may not know all about it, or he may not know which kind is best 

 for preservative purposes. The main use of these preparations for 

 years has been the rendering of fabrics non-inflammable. This use 

 in the Royal Theatre of Munich has rendered the place fire-proof 

 by its use as a varnish in the fresco work, woodwork, scenery and 

 curtains. It is also used for hardening stone and protecting it from 

 the action of the weather. It was thus used many years ago, to ar- 

 rest the decay of the stones in the British Houses of Parliament. 

 The use of this medium for egg preservation is comparatively new, 

 especially in this country, and it is not to be wondered at that 

 dealers do not always supply just what is wanted. 



Different Names for Water Glass 



If we used the term soluble glass or "dissolved glass" in prefer- 

 ence to either water-glass or silicate of soda, it might better de- 

 scribe just what we want, although one of the other names might 

 be preferable when ordering of the druggist. This term expresses 

 exactly what the material is. When we buy it by the pint or quart, 

 we get dissolved glass. When we buy it dry, we get a soluble glass 

 powder sometimes like powdered stone, sometimes white and 

 glassy as to its particles. The powdered forms are supposed to 

 dissolve in boiling water, but they do not dissolve readily, and must 

 often be kept boiling for some hours. 



Water-glass is made by melting together pure quartz and a caus- 

 tic alkali, soda or potash, and sometimes a little charcoal. 



Several of our Experiment Stations have made some rather ex- 

 haustive experiments with this dissolved glass in preserving eggs. 

 The reports are, without exception, in favor of it. No other pre- 

 servative is reported as being equal to this one. The stuff is invari- 

 ably described as a thick or jelly-like liquid, and the proportions 

 recommended are one pint of the silicate of soda to nine pints of 

 water, although the Rhode Island Station reports experiments in 

 which as low as two per cent of water-glass was used with favor- 

 able results. This is done to find out how little could be used, but 



