72 REPORT — 1871. 



of copper or of potassium has been previously added to the nitrate of silver. 

 Some other forms were described as produced under peculiar circumstances, such 

 as long straight threads, of extreme tenuity, often changing their direction at a 

 sharp angle. 



A'ote on Fibrin. By Dr. John GoodmajST. 



The author having read a paper on the above subject at the Meeting of the 

 Association in Liverpool last yeai-, has been since tliat period constantly engaged 

 in a long series of experiments establishing the truth of the statements there set 

 forth. The following is an epitome of the results obtained. The experiments 

 were performed under the microscope : — 



1. Albumen immersed for some short time in cold water loses its characters as 

 albumen, and becomes transformed into a substance which the author asserts 

 exactl}' resembles blood-fibrin under the microscope. 



2. This substance exhibits intense attractive powers. 



3. It decomposes peroxide of hj-drogcn with effervescence. According to the 

 author's views, all these experiments showed that water is the primary source of 

 this change, and that until albumen is in some way subjected to the influence of 

 water, oxygen can exert no influence in producing this change. 



4. The rapidity or intensity of the transformation was not increased by raisijig 

 the temperature of the water. 



5. Ovalbumen does not />c?- se become transformed into fibrin by the ■^"oltaic 

 cuiTcnts, only to such an extent as its water of fluidity is available for this pur- 

 pose. 



6. But when diluted witli water the entire mass of albumen submitted to the 

 cuiTent was rapidly transformed into fibrin. 



7. When this .substance was submitted to potash it dissolved in three minutes, 

 whilst blood-fibrin required twelve hours and ovalbumen twenty-four hours for 

 solution. 



8. In strong hydrochloric acid both this substance and blood-fibrin dissolved in 

 twenty-four hours, whilst ovalbumen was not completely dissolved in sixteen 

 days. 



9. In all acid solutions of this substance, and of blood-fibrin precipitated by 

 alkalies, and of alkaline solutions precipitated by acids, tlie author asserts that he 

 invariably finds fibrinous rods and formations perfectly identical in their appear- 

 ance one withthe other, and without any coagulum peculiar to albuminous preci- 

 pitations; whilst on the other hand in similar solutions of albumen similarly pre- 

 cipitated, he finds as invariably a dense flocculent coagulum, without the presence 

 of fibrinous rods or other formations. AUraliue solutions, moreover, of albumen 

 precipitated by acetic acid gave always a dense white and flocculent coagulum, 

 and those precipitated by nitric acid gave a lemon-yellow precipitate, whilst 

 neither white nor lemou-yellow coagula occurred in similar precipitations from 

 like solutions of fibrin thus produced as blood-fibrin. The author maintains that 

 these experiments show that the substance thus produced by the agency of water 

 is genuine fibrin. 



Freliminanj Notice on a New MdUd of Testing Samples of Wood-NajiJitJia. 

 By William Haekness, F.B.M.S. 



The detection of wood-naphtha, when present in alcohol, is now comparatively 

 easy, but the converse problem, viz. the detection of alcohol in wood-naphtha, does 

 not seem to have occupied the attention of chemists generally. 



Methylated spirit, which is cheaper tlian wood-naphtha, is the only adulterant 

 likely to be used, and any simple mode of determining its presence must be of 

 some value to the chemist. One of the most common methods of examining a 

 sample of naphtha is to ascertain its boiling-point : but this is not reliable, as 

 difterent samples, even of the same specific gravity, may boil at different tempera- 

 tures, varj'mg from 1.38° F. to 156° F., and yet be free from ethylic alcohol. 



I he following method of testing sami:)les was discovered by the author whilst 



