Practical Hints. IS 
magnesium, either in wire or ribbon, when burnt in the air.— 
Philadelphia Photographer. 
Practical Hints. 
Dry Pocket Glue.—A valuable pocket glue is made by combin- 
ing 12 parts good glue and 5 parts sugar. The glue is boiled in 
the usual way till thoroughly dissolved ; the sugar is then put in, 
and the mass is evaporated till it is found to become hard on 
cooling. Lukewarm water melts it very readily, and the article 
proves useful for many purposes. 
To Restore Faded Writing.— Professor von Bibra finds that the 
best method to restore faded writing is to brush over it a mode- 
rately concentrated aqueous solution of gallo-tannic acid, wash 
with water, and dry the MS. at a temperature of about 150° Fah. 
If the writing has been done with any ink containing iron, it is 
revived in clear and very black characters, which retain their 
colour for a long time. 
To Transfer Engravings.—Soak the engraving to be transferred 
in water for a few minutes, then dry between two sheets of bibu- 
lous paper. Pass over the part to be transferred a coating of 
white varnish, made with the finest alcohol, which may be 
procured from any colourman. Should the first coat of varnish be 
absorbed, give a second coat; then quickly apply the engraving, 
using a cloth to make it thoroughly adhere to the body to which 
the transfer is to be made. Allow to dry for four hours ; then wet 
the back of the engraving, and rub with the finger, a sponge, or a 
cloth, to remove the paper, until the image is seen with all its 
details. -Give a coat of the same varnish, and allow to dry. 
To Mount Starches.—The following formula is taken from 
Dr. Beale’s ‘Microscope in Medicine” 1878:—Anilin blue, 
4 gr. ; Distilled water, + 0z.; Alcohol, 25 drops. Make a mixture 
of equal parts of glycerine and water, to which add a very little 
acetic acid, only two or three drops to 1 oz. To this mixture of 
glycerine add the anilin blue solution until the mixture is of a 
decided blue colour; a drop of this placed on a slide and some of 
the starch is dusted on the top, which is done by touching the 
starch with a camel’s-hair pencil, and then slightly shaking the brush 
over the top of the coloured glycerine. The starch sinks in and 
mixes ; the cover is applied, pressed down quite firmly against the 
slide, and all excess of the glycerine removed. ‘The slide is then 
transferred to the turn table and then a layer of dammar or balsam 
