CHEMISTRY. 



107 



other way than as the nucleus of the com- 

 pound, carbon radicals in all these cases play- 

 ing the subordinate parts, there is every reason 

 to expect that complex alcohols containing 

 silicon only will yet be obtained. 



New Aniline "Color. The Bulletin of the 

 Paris Chemical Society describes a new ani- 

 line color, cinnamon -brown. This color 

 yields, on wool, silk, and cotton, a fine brown, 

 which may be varied at pleasure by the addi- 

 tion of blue, red, or yellow dye-wares. On 

 silk and wool it is applied without mordant. 

 It is dissolved in warm water, and filtered 

 after cooling. For silk it is acidulated with 

 tartaric acid. For wool one kilo, of sul- 

 phate of soda, and 250 grammes of sulphuric 

 acid, are taken to 20 kilos, of wool. The 

 dyeing is performed at a boiling heat. Cotton 

 is previously mordanted with tannin. Cinna- 

 mon-brown is obtained by means of one of the 

 products formed in the manufacture of ma- 

 genta. It is an acid salt of crysotoluidin, Cji 

 ILjiXt, a base derived from tolnidin, by the 

 elimination of hydrogen 3C7H>N 3Hj=C,i 

 IIjiN. The base is insoluble in water, and is 

 separated from the solution of its salts by alka- 

 lies, in the form of a light-yellow precipitate. 

 Its neutral salts are sparingly soluble in boil- 

 ing water, which splits them up into an in- 

 soluble basic salt and a soluble acid salt. The 

 solution of the acid salts is of a yellowish- 

 brown color ; the alcoholic solution of the free 

 base is a pure yellow. This shade is obtained 

 on dyeing in a bath of the acid salt mixed 

 with an alkali. 



Passage of Gae through Vegetable Colloid 

 Membrane*. The experiments made by Gra- 

 ham with caoutchouc, to show the passage of 

 gas through thin colloidal membranes, have 

 been repeated by Barthelemy with leaves of 

 certain varieties of Begoniaceae. In an account 

 of liis process to the French Academy, M. 

 Barthelemy says that, though it was difficult 

 to preserve in the several experiments the 

 same condition of external pressure, tempera- 

 ture, and hygrometric state, the numbers 

 sufficiently show that oxygen passes more 

 quickly than nitrogen, and that air thus dia- 

 lyz>;d contains on an average thirty-six per cent, 

 oxygen (a number slightly under that which 

 Graham obtained with caoutchouc). In an- 

 other experiment, having made COi pass over 

 the membrane, he marked the point to which 

 mercury descended in an hour ; then, passing 

 nitrogen or oxygen, he marked how long the 

 mercury took to descend to the same level. 

 The results closely agreed with Graham's, 

 and warrant the conclusion that the natural 

 colloidal surfaces of plants have for CO, an 

 admissive power thirteen to fifteen times great- 

 er than that for nitrogen, and six to seven 

 times (freater than that for oxygen. Carbonic 

 anhydride passes less quickly than hydrated 

 carbonic acid. The author remarks that 

 " cnticnlar respiration appears sufficiently 

 proved by the presence of colloidal membrane 



in all organs ; by the similarity (physical and 

 chemical) between this membrane and caout- 

 chouc ; by Graham's experiments; by measure- 

 ments of the passage of gas through colloidal 

 membrane ; and, last, by M. Boussingault's 

 experiments, which attribute to the upper 

 surface of leaves devoid of stomata a decom- 

 posing power greater than that of the under 

 face covered with these small orifices." 



Antimony Terchloride a a Reagent for Oih. 

 Dr. Isidor Walz, in a communication to the 

 American Chemist, details as follows the re- 

 sults of his investigation on the subject of re- 

 agents for testing oils : He first took up an- 

 hydrous stannic chloride, but abandoned it 

 after trying it with several oils, because the 

 abundant fumes which it gives off render it a 

 very disagreeable reagent to work with. He 

 found anhydrous stannic chloride completely 

 soluble in benzine ; the oil after a time turns 

 reddish-brown and is partially resinified, while 

 large acicular crystals form throughout the 

 liquid. Turning next to antimony terchloride, 

 he attempted to use Meek's solution, sp. gr. 

 1.345, but found that this would not mix suffi- 

 ciently well with oils to produce satisfactory 

 reactions. Good results were, however, ob- 

 tained by concentrating this solution on the 

 water-bath to a syrupy consistence. Antimony 

 terchloride as thus prepared reacts with all 

 the oils which ho tried, animal, vegetable, es- 

 sential, and those derived from petroleum. In 

 the case of the animal and vegetable oils there 

 ensues generally a rapid darkening, the color 

 turning to a reddish, greenish, or dirty brown, 

 accompanied generally by a perceptible rise in 

 temperature, and increased consistency of the 

 oil, the latter becoming viscid, and in one or 

 two cases solidifying altogether. After the 

 lapse of a little time a stratum of antimony- 

 chloride solution separates at the bottom of 

 the test-tube, which has a greenish-yellow 

 color. The oils for which this general descrip- 

 tion may suffice are rape-seed, poppy-seed, tal- 

 low, neat's-foot, and sperm. Some character- 

 istic reactions were observed with the follow- 

 ing: 



1. Olive-oil (three samples) forms a whitish 

 emulsion, rapidly passing through light to dark 

 green. No perceptible rise of temperature. 



2. Cotton-seed oil (two samples) turns 

 chocolate-brown, with evolution of consider- 

 able heat. One of the samples solidified a 

 few minutes after the test was applied, so that 

 the tube could be inverted, while still warm, 

 without the oil flowing out. 



3. Neat's-foot oil turns pink, subsequently 

 darker and thicker. The temperature rises. 



4. Resin -oil turns purple. Though the 

 color becomes gradually darker, the peculiar 

 purple tint can be recognized even after n 

 long time. 



Of the petroleum-oils he tried gasolene, ben- 

 zine, and kerosene. After shaking, two strata 

 separate in the test-tube. A portion of the oil 

 is resinified, the resin adhering to the sides of 



