48 



SCIENCE. 



mere supposition, to be true, what possible bearing can 

 it have upon the result ? Why should not professional 

 actors be as good subjects as any other persons ? This 

 objection seems to me about on an equality with some 

 others which] I have heard, e.g., that all the subjects 

 were trained to perform to suit the occasion. Your asser- 

 tion that " the subjects of Dr. Beard are selected from the 

 nervous classes of our population," is in direct contra- 

 diction to^the doctor's declaration. In no sense can I 

 regard your criticism as quite fair. Moreover, you have 

 neglected to mention two of the most convincing demon- 

 strations of the reality of the phenomena, — I refer to the 

 extraction of two teeth from one subject, and the appli- 

 cation of actual cautery to another. The opinion seems 

 to be very common that the phenomena of mesmeric 

 trance cannot be genuine unless all persons can be 

 brought under its influence. A very little reflection will 

 show that this is an erroneous opinion. There is much 

 more that might be said upon the subject, but my pur- 

 pose is only to correct the erroneous impressions which I 

 am sure your article will give to many readers. I hope 

 the columns of " SCIENCE " will be held open for a free 

 discussion of these phenomena. R. HITCHCOCK. 



To the Editor of " Science :" 



In Dr. Spitzka's suggestive " Notes on the Anatomy of 

 the Encephalon, etc.," in " SCIENCE," No. 29, occurs the 

 following passage : 



" Now, the third ventricle, as shown by Hadlich and 

 Wilder, extends over the entire thalami." 



I regret to be obliged to make a correction. The pas- 

 sage contains two distinct statements : the one, that the 

 third ventrical extends over the entire thalami, and the 

 other that such was shown to be the case by Hadlich and 

 myself. 



Since upon this point — as upon all others presented in 

 the article — no exact references are given, I will not speak 

 now of Hadlich's views ; but no such statement has ever 

 been made by me, and I am at a loss to understand how 

 Dr. Spitzka can have gained that impression. On the 

 contrary, my paper " On the Foramina of Monro in the 

 Domestic Cat," read at the Boston meeting of the A. A. 

 A. S., but not yet published, included an expression of 

 my belief that, in the cat, the dorsal limit of the third ven- 

 tricle on each side corresponds with the Habena, (the so- 

 called " peduncle of the pineal body,") along which the 

 Endyma (the lining membrane of the ventricles), is re- 

 flected from the mesial surface of the thalamus toward the 

 opposite side. Hence, only the mesial aspect of each 

 thalamus is "in the third ventricle," the remaining and 

 much larger part of the surface being wholly extra-ventri- 

 cular. Burt G. Wilder. 



ITHACA, N. Y., January 26, 1881. 



BOOKS RECEIVED. 



Bulletin No. 3 of the Illinois State Laboratory of 

 Natural History at Normal, 111., is a pamphlet of 160 

 pages, containing papers by the Director of the Labora- 

 tory, Prof. S. A. Forbes, on the following subjects : On 

 some Interactions of Organisms ; The Food of Fishes*; 

 Acanthopteri ; On the Food of Young Fishes ; The Food 

 of Birds ; Notes on Insectivorous Coleoptera. Likewise 

 a brief but significant paper — Notes upon the Food of 

 Predaceous Beetles, by Mr. F. M. Webster, who has in- 

 dependently come to the same conclusion as Prof. Forbes 

 that the Carabidas, in place ot being exclusively insect- 

 ivorous as is generally supposed, can, and in fact do, de- 

 rive considerable sustenance Irom grains, grasses, and 

 other vegetable substances. 



The instructiveness and practical as well as scientific 

 value of the researches which form the basis of these 

 papers may be inferred from their titles, and from Prof. 



Forbes' well known accuracy and enthusiasm. But they 

 are also very interesting and entertaining reading, and 

 will thus be more apt to reach the minds of many who 

 would otherwise fail to profit by the stores of informa- 

 tion they contain. It would be well for other states to 

 make the slight provision required for carrying on sim- 

 ilar investigations into the food habits of the Birds, 

 Fishes and Insects found within their limits. 



B. G. W. 



CHEMICAL NOTES. 



Detection of Iodine in Bormine and Metallic Bro- 

 mides. — A few drops of the bromine in question are 

 placed in a small porcelain capsule, 30 c.c. of a solution 

 of potassium chlorate, saturated in the cold, are added, and 

 the liquid is boiled till colorless. The solution is then 

 poured into a test-tube, allowed to cool, mixed with a few- 

 drops of a solution of morphine sulphate and a little chloro- 

 form.' If the chloroform takes a violet color, iodine is 

 present in the sample. The morphine solution is prepared 

 by dissolving 0.5 grm. morphine in an excess of dilute sul- 

 phuric acid, and diluting to 50 c.c. In examining potas- 

 sium bromide the solution is mixed with 2 or 3 drops of 

 pure bromine water, and a few c.c. of a cold saturated so- 

 lution of potassium chlorate, and further treated as above. 

 — A. Jorissen. 



Determination of Sulphur in Iron Pyrites. — On ox- 

 idizing pyrites with nitric acid and precipitating the sul- 

 phuric acid from the ferriferous solution, slightly acidified 

 with hydrochloric acid, there is always obtained a barium 

 sulphate, contaminated with iron, and still the results were 

 too low. The following process is, therefore, adopted : I 

 grm. pyrites was mixed in a large covered crucible with 8 

 grms. of a mixture of equal parts potassium chlorate, 

 sodium carbonate, and sodium chloride. The crucible is 

 heated at first gently so as to dry the contents, which are 

 afterwards melted at a high temperature. The mass when 

 cold is treated with boiling water, and the solution together 

 with the deposit is introduced into a measuring-flask of 

 200 c.c. filled up, filtered, and the sulphuric acid is deter- 

 mined in aliquot parts, say 50 c.c. The insoluble residue 

 does not retain any sulphuric acid. In this manner the 

 use of nitric acid is evaded. The decomposition of the 

 potassium chlorate is complete. — Bernhard Deniecon. 



Contribution to Electrolysis. — L. Schucht describes 

 the electrolytic determination of uranium, thallium, indium, 

 vanadium, palladium, molybdenum, selenium, and tellu- 

 rium. For qualitative analysis he uses a strong test-glass, 

 10 to 12 cm. high, and 1.5 cm. wide, fitted with a cork 

 coated with paraffin. Two platinum wires, 1)4 rn.m. in 

 thickness, pass through the cork down to the bottom, and 

 are connected above the cork with the polar wires of the 

 battery by means of small binding screws. This decompo- 

 sition tube may be held in a wooden clamp. After the 

 current has passed through the solution to be analyzed for 

 ten to fifteen minutes, the stopper with the wires is drawn 

 out, without interrupting the current, and the deposited 

 metal is determined by its color, lustre, solubility in acids, 

 &c. The manner of decomposition and the slight or strong 

 evolution of gas is noticed. The solution is completely 

 precipitated, rendered alkaline, and again electrolysed, 

 after the wires have been cleansed. Copper is recognised 

 by its color, mercury by the precipitated globules, nickel 

 and cobalt by their lustre and sparing solubility in acids, 

 zinc and cadmium by their color and solubility in potassa. 

 The formation of peroxides is characteristic for lead, silver, 

 bismuth, thallium, manganese. Bismuthic acid is gradually 

 formed, whilst the peroxides of lead, silver, and thallium 

 are deposited at the beginning of the precipitation. Silver 

 peroxide dissolves in ammonia with liberation of nitrogen. 

 The decomposition of the alkalies and alkaline earths is 

 best effected in a U-tube. The hydroxides of the latter are 

 separated in a voluminous form ; those of calcium and 

 magnesium in white crusts. The hydroxides of barium, 

 strontium, and the alkalies dissolved on the negative wire, 

 Btrg-und Uiittcn Zeitung, 39, 121. 



