114 



CHEMISTRY. 



and is highly commended in some of the Eng- 

 lish journals. A writer in the Chemical News 

 says: 



Solutions of chloralum from 1005 to 1010 sp. gr., 

 i. e., containing from 1 to 3 parts of chloride to 140 

 or to 70 parts of water, are sufficiently strong to keep 

 fish and meat which have been simply dipped in 

 them and then suspended in the dry air. The quan- 

 tity of antiseptic used is but a small fraction of one 

 per cent., and the preservation complete if the neces- 

 sary precautions have been taken. According to my 

 observations, chloralum is more active than sulphur- 

 ous acid. 



Both sulphurous acid and chloralum are available 

 when the carbolic and cresylic acids cannot be used, 

 owing to their smell, flavor, and causticity. I have 



eral years, and they stand unrivalled for a limited 

 number of medical and economic purposes, but 

 chloralum covers a much larger field ot useful appli- 

 cations, and we are not yet acquainted with a tithe 

 of these. Proof positive of its unequalled value is the 

 extraordinary rapidity with which medical men have 

 taken it up, and reported on its use in the treatment 

 of wounds, arresting the fetor of cancer, cheeking the 

 throat lesions in dipntheria and scarlatina, preventing 

 suppuration, absorbing from the air the odor of fresh 

 paint, in a manner not yet explained, in addition to 

 destroying many fetid emanations which are simply 

 masked by carbolic acid, and which are offensive, if 

 not even actively poisonous. 



The London Cotton Mills, Limited, have under- 

 taken the manufacture of wools and waddings con- 

 taining a definite percentage of chloride of alumin- 

 ium. Cotton-wool thus treated is styptic and anti- 

 septic. It maybe used as a padding under bed-sores 

 for the absorption of fetid secretions, and suspended 

 in the air as a filter of atmospheric currents. A cur- 

 tain containing a layer of this wool, within a light 

 porous covering, suspended over the door of a sick- 

 chamberj will very materially check the dispersion of 

 fever-poisons from a sick-room into other parts of 

 a house. 



Tests for Alum in 'Bread. Mr. R. 0. Moffat, 

 of Glasgow, having been engaged to report 

 professionally on the occurrence of alum in 

 some breads, found the usual tests untrust- 

 worthy and awkward. After making about 

 t\vo hundred experiments, none satisfactory, 

 on the old methods, he adopted a process 

 known as Horsely's, which recommends the 

 bread to be placed in vinegar for a short time, 

 the vinegar to be strained off and a little am- 

 monia added to the clear liquor to neutralize 

 the acid. An alcoholic solution of logwood 

 was then added, which, it was said, gave the 

 solution a blue color when alum was present. 

 Fourteen loaves had been given him to test, 

 and with Mr. Horsely's process every one of 

 them contained alum ; but, in experimenting 

 further, he found that the blue color was pro- 

 duced when no alum was present, and that the 

 most reliable test for detecting the presence of 

 alum in bread or flour was the simple alco- 

 holic solution of logwood, without any of the 

 burning, boiling, or other processes. One hun- 

 dred and twenty grains of chip-logwood, di- 

 gested in eight ounces of methylated spirits for 

 eighteen hours, then filtered, yielded a solution 

 which, when brought in contact with bread 

 or flour free from alum, produced a pale- 

 yellovr or straw color, but a dark red when 



alum is present. "With this test he had 

 found that only one of the fourteen loavea 

 contained alum showing that alum is not used 

 so extensively for the purpose of whitening 

 bread as has been supposed by many. 



Cheap Hydrogen. The Journal of the So- 

 ciety of Arts records successful experiments 

 by MM. Tessie du Motay and Marechel (discov- 

 erers of a cheap mode of obtaining oxygen) 

 to make hydrogen economically. Alkaline and 

 earthy hydrates, such as hydrate of potash, 

 soda, strontia, baryta, and chalk, are mixed 

 with charcoal, coke, anthracite, pit-coal, or 

 peat, and heated to a red heat, when they are 

 speedily decomposed into carbonic acid and 

 hydrogen, without further loss of heat than is 

 due to the production of those two gases. The 

 hydrates (especially those of chalk or lime) 

 can be used over indefinitely in this process, 

 provided they are moistened each time with 

 water, so as to reproduce the decomposed 

 hydrates. In this operation the hydrogen is 

 generated without any special production of 

 steam, and may thus be produced without any 

 other generating apparatus than the retorts 

 themselves. These retorts, not being exposed 

 to the direct action of the steam, are not sub- 

 ject to any interior alteration or damage. It 

 follows, therefore, that the hydrogen gas, 

 produced by the decomposition of the above- 

 named hydrates by means of carbon, can be 

 generated at a very small cost, and with the 

 same facility as carburetted hydrogens from 

 the distillation of pit-coal or other organic 

 hydrocarbon matter. These alkaline and 

 earthy alkaline hydrates may be mixed with 

 the different mineral or vegetable combusti- 

 bles, either in a definite chemical proportion, 

 or without a fixed or determinate proportion, 

 and in any suitable distilling or heating ap- 

 paratus, in order to produce, when heated to 

 a red heat, hydrogen gas for illuminating and 

 heating purposes. The advantage of the pro- 

 duction of hydrogen as cheaply as oxygen, 

 which has been obtained, is likely to create a 

 revolution in many industries, and especially 

 in metallurgy. A cheap method of producing 

 a great heat in order to reduce metals, such 

 as platinum, gold, silver, and iron, has long 

 been sought for in Europe, where the oxy- 

 hydric blow-pipe is now used to melt the plati- 

 num in a calcium crucible. By this discovery 

 it becomes possible to obtain an immense heat 

 which could be regulated by a simple tap. 

 Enamellers and porcelain-makers may thus 

 get rid of one of their greatest troubles. 



New Chlorine Process. The use of man- 

 ganese is now dispensed with in making chlo- 

 rine at the Widnes Alkali Works, England. A 

 mixture of air and hydrochloric-acid vapor is 

 passed over a mass of broken brick heated to 

 700 Fahr., that has previously been soaked in 

 a solution of blue vitriol and dried. An almost 

 complete decomposition of the acid takes 

 place. The copper salt acts in some unknown 

 way, as it is found at the end of the operation 





