256 ANNUAL OF SCIENTIFIC DISCOVERT. 



the number of vegetable or animal fibers in these mixed fabrics can 

 be ascertained with sufficient exactness. 



This test may also be employed with most dyed stuffs ; at least it may 

 be applied to orange red, fawn color, rusty yellow, violet, every kind of 

 blue, and some browns. Thus, as the mordants usually employed, as 

 eumina, and salt of tin, and lead and iron compounds, don't produce any 

 essential change in the yellow color of picric acid, but only deepen it 

 more or less, stuffs dyed with the above named colors, undergo no 

 remarkable change by being dipped in the test-solution if they consist 

 of vegetable fiber ; but a change always takes place if animal fiber is 

 present, and this will always indicate with perfect certainty whether 

 a stuff consist of animal or vegetable fiber, or of a mixture of both. 

 Thus wool dyed red becomes changed by picric acid into orange-red, 

 or orange according to the shade of the original color, whilst rusty 

 yellow becomes bright yellow, blue colors green, and green, greenish- 

 yellow. Chemical Gazette. 



DETECTION OF COTTON IN UNBLEACHED LINEN. 



A piece of the stuff to be examined is well washed with boiling 

 water, and dried ; then laid in a mixture of 2 parts of dried nitrate 

 of potash and 3 parts of ordinary sulphuric acid, and left in inti- 

 mate contact with it for 8-10 minutes, according to the strength of 

 the fabric. After a complete washing and drying, the piece of stuff 

 which has been changed by the nitric acid is decocted with ether, to 

 which some alcohol is added ; the more consistent the collodion thus 

 obtained, the more cotton was there in the linen. If it is wished to 

 determine the quantity of cotton, it is only necessary to weigh the 

 linen after it has been boiled with water and dried, then to proceed 

 as above, separate the collodion obtained from the residue (which is 

 unchanged linen,) wash this well with some ether and alcohol, dry 

 and weigh it ; the loss of weight gives the quantity of cotton with 

 tolerable accuracy. Arcliiv. der P/iarm. Zimmermann. 



ARTIFICIAL MALACHITE. 



Rose, of Berlin, has mentioned the following process as being capable 

 of simulating in appearance, whilst it is identical in composition 

 with, natural green malachite. Precipitate a solution of sulphate of 

 copper in the cold by carbonate of soda, or of potash, allow the pre- 

 cipitate which is voluminous at first to cohere, finally dry it, and wash 

 it. By polishing, the characteristic appearance of malachite may be 



brought out. 



NEW ANAESTHETIC. 



At a recent meeting of the London Medical Society, Mr. Richard- 

 eon read a paper on the anaesthetic properties of the common Puff 

 Ball (Lycoperdon Proteus). His attention was directed to the subject 



