CHEMISTRY. 



103 



liquid has taken a very fine blue tint, very 

 dark, and a certain quantity of phenolcyanine 

 is found at the bottom, and adhering strongly 

 to it. That which remains in solution can be 

 collected by saturating the liquid with salt. 

 The product is thrown on a filter, and the new 

 substance dissolved in hot alcohol or benzol, 

 from which it is obtained by evaporation. 

 With regard to its properties and composition, 

 Dr. Phipson says : 



Thus obtained, phenolcyanine is a resinous sub- 

 stance of a very dark blue, nearly black, and 

 showing metallic copper-colored reflections like in- 

 digo. In alcohol, it forms a fine deep-blue solu- 

 tion, in ether a reddish purple-blue, and in benzol 

 a reddish purple solution. Concentrated sulpliur- 

 ic acid dissolves it easily, forming a bluish-green 

 liquid ; hydrochloric acid has little action ; and 

 nitric acid forms a nitrous compound very dif- 

 ferent from picric acid. Phenolcyanine is very 

 slightly soluble in water, but dissolves in hydrated 

 alcohol to which ammonia is added, and this solu- 

 tion can be considerably diluted with water. These 

 alkaline solutions are deep sky-blue by day, but of 

 a vinous red by night or when a flame is seen 

 through them. Acids redden these solutions, and 

 alkalies bring back the blue, as with litmus. Nas- 

 cent hydrogen reduces phenolcyanine, and renders 

 it completely colorless, put when the solution re- 

 mains exposed to the air in presence of ammonia the 

 blue color soon returns. A mixture of ferrous sul- 

 phate and lime does not destroy the color of phenol- 

 cyanine as it does that of indigo-blue ; so that the 

 former rather resembles the colored derivatives of 

 orcine than it does indigo. Phenolcyanine melts 

 very easily, and can be partially volatilized in purple 

 vapor; the remainder is decomposed, and leaves a 

 porous charcoal. 



My analyses of this new product have not been 

 very satisfactory, on account of the very small 

 quantity which I have yet had at my disposal for 

 this purpose ; I believe, however, that I can assign 

 to it the formula C,,H,NO,, or C 1 ,H,NO,= C,,H,NO,, 

 + 2HO. According to the most recent analyses, 

 orcinp is C H H,NO,, and indigo-blue C,,HjNO.,, so 

 that it is possible both may some day be formed 

 from phenolcyanine. I hope to be able soon to refer 

 to its composition again. 



Alcohol in Bread. Some years ago a com- 

 pany was formed in London for the purpose of 

 saving and utilizing the alcohol developed in 

 the process of bread-making. The object, 

 says Miller, was attained by performing the 

 baking in closed ovens, furnished with a still- 

 head for collecting and condensing the vapors. 

 The project was, however, soon abandoned, 

 and failed as a commercial speculation, owing 

 in a great measure to the dry, unpalatable na- 

 ture of the bread produced. It was Miller's 

 opinion that during the baking " the alcohol 

 formed by decomposition of the sugar, which 

 corresponds in quantity to that of the carbon- 

 ic anhydride, is expelled." Some experiments 

 made by Mr. Thomas Bolas show that by dis- 

 tilling two ounces of ordinary bread in water, 

 and rectifying the distillate, it is easy to obtain 

 a quantity of alcohol which is quite sufficient 

 to show that all the spirit does not pass away 

 in the process of baking. The author says : 



In order to determine the amount of alcohol 

 quantitatively, about one pound (I kilo.) of each 

 ample was distilled with water, an addition of 



about I c.c. of oil being made to moderate the 

 frothing, and the distillate was rectified a sufficient 

 number of times, the alcohol being finally deter- 

 mined in the usual way. The results of the exam- 

 ination of six samples of new bread purchased at 

 different shops in London are embodied in the fol- 

 lowing table : 



Percentage of Alcohol. 



I O.SH5 



II 0.221 



m o.4oi 



IV 0.38 



V 0.249 



VI 



Average 0.314 



These samples were subjected to distillation as 

 soon as practicable after baking, they having been 

 obtained almost immediately after the opening of 

 the shops; and, in order to ascertain the loss of 

 alcohol which bread undergoes on keeping, portions 

 of Nos. III. and VI. were exposed to the air in a 

 moderately warm room for a week, after which time 

 it was found that nearly two-thirds of the alcohol 

 had evaporated, the amount remaining being 0.132 

 per cent, and 0.120 per cent, respectively. Although 

 the presence of alcohol in the machine-made (aerated) 

 bread would naturally create surprise, a portion 

 of this kind of bread was, for the sake of compari- 

 son, submitted to distillation as in the above cases, 

 and, as might have been expected, no alcohol was 

 detected. 



It is probable that the amount of alcohol contained 

 in bread is too small to be of any ' dietetic impor- 

 tance, but it may bo perhaps worth while to notice 

 that forty two-pound loaves are about equal in al- 

 coholic strength to an ordinary bottle of port. 



I hope shortly to determine the amount of alcohol 

 which dough loses on baking, not only when it is 

 baked in large masses, but also when it is divided 

 into small pieces (rolls) before baking. 



_ Examination of Blood-Staim. A commis- 

 sion of French medical men have been investi- 

 gating the methods of examining blood-stains. 

 They point out that, in the present day, it is no 

 longer possible to rest satisfied with the phys- 

 ical characters observed by the naked eye. 

 But the microscope, either alone or in con- 

 nection with chemical analysis and the spec- 

 troscope, enables us to obtain a correct diag- 

 nosis formerly impossible in a great number 

 of cases. Two conditions may occur : 1. 

 When the stain is of recent date, or supposed 

 to be so, the red corpuscles should be particu- 

 larly examined, and every care taken to pre- 

 serve them without change. The stains must 

 not be washed with water, as the heematine 

 may thus be altered. Among fluids which are 

 destructive of blood-corpuscles, are enumer- 

 ated water, and particularly hot water, acetic, 

 gallic, hydrochloric, and sulphuric acids ; of 

 the alkalies, potash and soda, even in weak 

 solution ; ether, and chloroform, and many 

 other reagents. Alcohol, chromic and picric 

 acids, and bichromate of potash, preserve the 

 corpuscles, though they alter their form. The 

 preservative fluids are those whose composi- 

 tion approaches nearest to sernm, such as the 

 iodized serum of Schultze, consisting of amni- 

 otic fluid, to which are added a few drops of 

 the tincture of iodine ; or, better, a fluid com- 

 posed of white of egg, 30 grammes; distilled 

 water, 270 grammes ; and chloride of sodium, 



