SCIENTIFIC SUMMARY. 
321 
phenomenon that the capillarity of the fissure has a real influence on the 
nature of the products of the decomposition ; that the salts or the crystalli- 
sations are not always those indicated by theory ; that the double de- 
composition often goes to the extent of reduction of the metal. — Vide 
Comptes Pendus, May 13. 
Supposed Aniline Colours from Flesh . — Herr Erdmann fancies he has dis- 
covered a mode of producing the aniline dyes from flesh. Some time since 
he observed that a piece of roast veal had a reddish appearance on its surface. 
On transferring the red matter to various substances he found that under 
the influence of heat and moisture if increased in quantity. The chemical 
properties of the colouring matter to a certain extent resemble tryphenyl- 
rosaniline. The fact that large numbers of vegetable and other spores were 
formed with the red colouring matter is quite sufficient to account for the pro- 
duction of the colour. The new dye (!) is evidently of the same order as 
“ showers of blood ” and so forth, due to the development of low vegetable 
organisms. — Vide Journal fur Praktische Chemie. 
How to cover Floivers with Alum Crystals. — A trans- Atlantic contemporary 
describes a simple method of covering fresh-flowers with alum crystallisa- 
tion. It is as follows : — Make baskets of pliable copper wire, and wrap 
them with gauze. Into these tie to the bottom violets, ferns, geranium 
leaves, chrysanthemums — in fact, any flowers except full-blown roses — and 
sink them in a solution of alum of one pound to the gallon of water, after 
the solution has cooled, as the colours will then be preserved in their 
original beauty, and the crystallised alum will hold faster than when from a 
hot solution. When you have a light covering of distinct crystals that 
cover completely the articles, remove carefully, and allow them to drain for 
twelve hours. 
The Proportion of Acid and Sugar in ripening Fruit . — At the meeting of the 
Chemical Society, held on the 16th of May, an interesting paper by Dr. 
A. Dupre, upon the above important subject was read by the secretary. It 
has been stated by Continental chemists that, as the fruit ripens the acid 
(malic and tartaric) becomes converted into sugar. This is the point to 
which Dr. Dupre especially devoted his enquiries, and which he believes 
he has cleared up by showing that the Continental view is inaccurate. 
Dr. Dupre collected and experimented upon a hundred berries of Riesling 
grapes gathered at intervals of a month, commencing with September last, 
and the amounts of tartaric acid, free and combined, and also of sugar, 
were determined in the separated j uices. The proportion of sugar increased 
in order of time from 2-98 to 12V0, and even to 16*20 per cent, in the juice 
of the perfectly ripe fruit ; whilst the entire berries showed but a slight 
diminution or no appreciable change in the total amount of acid present. 
The saccharine matter could not, therefore, have been directly derived from 
the organic acid or its salts contained in the grape ; but the author thinks it 
possible that the presence of such acid effects a change resulting in the 
production of sugar similar to that known to occur in the conversion of 
starch into sugar by the action of sulphuric and other acids. Further 
experiments, even more decisive in their character, were made upon Gutedel 
and Muscatel grapes, gathered at the same time and from the same vine, 
but in various stages of ripeness. In some of the unripe berries there was 
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