140 



DEFINITION OF TF.RMS. 



requires oxygen gas, and a certain de- 

 gree of heat and moisture to be present. 

 Seeds do not germinate well if they are 

 exposed to the action of light. 



Oxymuriatic acid causes seeds to vege- 

 tate more rapidly when they are steeped 

 in it or watered with it; supposed to he 

 caused by the facility with which this 

 acid parts with its oxygen. This acid 

 seems even to augment the power of 

 seeds. Cases are stated where seeds had 

 been long kept, and refused to germinate, 

 grew rapidly when treated with this 

 acid. When a seed is jdaced in favorable 

 circumstances it gradually imbibes mois- 

 ture, and very soon after emits a quantity 

 of carbonic acid gas, even though no oxy- 

 gen gas should be present. If no oxy- 

 gen gas be present, the process stops here, 

 and no germination takes place. But if 

 oxygen gas be present, it is gradually ab- 

 sorbed by the seed; and at the same time 

 the farina of the cotyledons assume a 

 sweet taste. The quantity of oxygen 

 gas absorbed during germination, isalwaj'S 

 proportional to the carbonic acid gas 

 emitted; that is, the carbonic acid emit- 

 ted contains in it precisely the same 

 quantity of oxygen as has been absorbed. 



Gilding is the application of gold to 

 the surfaces of bodies. 



To write on paper with letters of 

 gold, put some gum arable into common 

 writing ink, and write with it in the 

 usual way. When the writing is dry, 

 » breathe on it; the warmth and moisture 

 soften the gum, and will cause it to fasten 

 on the gold-leaf, which may be laid on in 

 the usual way, and the superfluous part 

 brushed off. Or instead of this any 

 japanner's size may be used. 



To make shell-gold. — Grind up gold- 

 leaf with honey in a mortar, then wash 

 away the honey with water, and mix the 

 gold powder with gum water. This may 

 be applied to any article with a camel's 

 hair pencil, in the same way as any other 

 color. — Glasses, &c. may be gilt by 

 drawing the figures with shell gold mix- 

 ed with gum arable and a little borax. 

 Then apply sufficient heat to it, and last- 

 ly burnish it. The work being thus gilt, 

 it is suffered to remain about twenty-four 

 hours, when the parts that are designed 

 to be burnished, are polished with a dog's 



tooth, or, what is better, with an agate; 

 burnisher. The gilding must not be 

 quite dry when burnished; there is a 

 state proper for the purpose, which isi 

 only to be known by experience. 



Gluten, a substance found in wheat 

 and various other vegetables, and con- 

 stituting an essential ingredient in the 

 formation of bread. It seems also to con- 

 stitute the essential part of yeast. It is 

 exceedingly, tenacious, ductile, and elas- 

 tic, hence the superior lightness of wheat 

 bread to that made from other grain: the 

 carbonic acid gas produced by fermenta 

 tion is retained by the gluten. Theforceol 

 this gas acting on the gluten causes it to 

 swell and form what is usually called 

 light bread; wheat contains a larger por- 

 tion of gluten than any other grain. Il 

 is also used for varnish, and a ground foi 

 paint, and is said in many cases to con- 

 stitute the base of the substance called 

 bird lime. 



Gneiss, in mineralogy, is compose<3 ;= 

 essentially of felspar, quartz, and mica il's 

 forming plates which are laid on each I'JS 

 other, and separated by thin layers o k 

 mica. ' 



Gnomen, in dialling, the style, pin, oi 

 cock of a dial, which by its shadow show; 

 the hour of the day. The gnomen o 

 every dial represents the axis of thf 

 world. 



Grafting or grajfing, in gardening 

 is the insertion of a scion into a stock oi 

 stem raised for the purpose. The usua 

 time for grafting is from mid-Februarj 

 to mid-March, but in a forward seasor 

 sooner, and in a backward one later. 



Let the scions be taken from the 

 trees two or three weeks before they arc 

 wanted: set them on end half buried (in 

 mould or sand nearly dry) in a garden 

 pot placed in a cool room. They should 

 he. taken from the outside of healthy trees 

 just in their prime. Budding may be 

 performed from the middle of June to the 

 middle of August. 



Granite, a genus of stones of the 

 order of petrae, belonging to the class ol 

 saxa. The principle constituent parts ol 

 this stone are felspar or rhombic-quartz, 

 mica and quartz. 



Graphites, in mineralogy, a mineral 

 consisting principally of carbon, with a 



I;? 



K 



