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POPULAR SCIENCE REVIEW. 
alizarine and purpurine, a small quantity of a third substance, which in com- 
position is allied to these two. The colour of its alkaline solution is almost 
the same as that of the alkaline solution of chrysophanic acid. Acids pre- 
cipitate it as a g-elatinous, flocculent, and amorphous mass, of a pale yellow 
colour. It crystallizes from the alcoholic solution in orange-yellow needles, 
and from the acetic acid solution in pale citron needles. The aqueous solu- 
tion, impregnated with acetic acid and boiled with silk, gives this a beautiful 
golden yellow dye. 
The Synthesis of Creatine. — At a late meeting of the Bavarian Academy, 
1 1 err J. Volkard read a paper on this subject. The author has already 
shown that sarcosine is methylamidoacetic ,acid, or acetic acid into the 
radical of which a residue of methylamine enters, having obtained it syn- 
thetically from chloracetic acid and methylamine. Having effected this 
synthesis he endeavoured, without success, to combine the sarcosin directly 
with the residue of urea, and so get creatine, thereby demonstrating syn- 
thetically the correctness of the view of the constitution of creatine founded 
on its analysis. He then imitated Herr Strecker’s synthetical method of 
forming glycocyamine in which glycocol is united to cyanamide. Glycocol 
bears the same relation to sarcosin that glycocymine bears to creatine. By 
bringing together sarcosin and cyanamide in solution, in water or alcohol, 
small portions of creatine are formed, the formation being rapid at a boiling 
heat. The author showed by a number of analyses and reactions that the 
creatine so obtained is completely identical with that obtained from meat- 
broth and from urine. 
Balsam of Beru. — In a paper published in the Proceedings of the Kaiser- 
liche Akademie of Vienna, Herr Kachler says that this substance suits well 
for the preparation of benzylic alcohol, free from admixture with other 
bodies. The balsam contains a notable quantity of cinnamate of benzylic 
ether, together with a resinous substance, which, treated with hydrate of 
potash, gives benzoic acid and protocatechuic acid. The same hydrate 
serves for obtaining the benzylic alcohol from the cinnamate of benzylic 
ether. A liundred parts of balsam of Peru yielded resin 32, benzylic alcohol 
20, crude cinnamic acid 46 parts. 
Volumetric Bstwiation of Sulphuric Acid. — A new feature in the Chemical 
News is an excellent series of abstracts of all the foreign memoirs on chemistry 
and physics. From this we select the following account of a method pub- 
lished in Dingier 8 Polytechnisches Joinmal, by the Rev. Dr. A. Coleman : — 
The solution to be experimented upon is coloured with litmus, and very 
carefully neutralised ; a solution of chloride of barium of known strength is 
added in exccs.s, and all the sulphuric acid thereby precipitated. Next, a 
titrated solution of carbonate of soda is added, in order to precipitate the 
excess of baryta; and next, again, the excess of soda solution used is esti- 
mated, voluiuetrically, by means of a titrated dilute sulphuric acid. During 
these operations no salt is formed which can injure the colour of the litmus. 
In case .salts miglit be present in the original solution, the bases of which 
could be precipitated by carbonate of soda, that precipitation is performed 
previous to the addition of soda. The filtrate, which contains the sulphuric 
acid conibined with soda, is neutralised, and again volumetrically titrated. 
The solutions required for this experiment are : — A solution of chloride of 
