Scientific Intelligence, Sfc. 153 



VIII. — Composition of Silk. 



Mulder of Rotterdam has lately made an analysis of silk. Some 

 yellow Neapolitan silk was boiled with distilled water until infusion 

 of galls no longer produced any precipitate; the solution was then 

 evaporated, — a thick gray substance remained. When treated with 

 water a portion of this matter dissolved ; it was gelatin : but the 

 greater part remained insoluble ; it was albumen. The boiled silk 

 being treated with' absolute alcohol afforded some yellow flocks, 

 cerin. The silk was then treated with hot ether. On evaporating 

 the latter a colourless residue remained. Digestion in weak caustic 

 potash took up some fatty matter from this residue, and when boiled 

 with it some resin was separated ; a red colouring matter was left 

 undissolved. The silk was then boiled with concentrated acetic acid. 

 Some albumen was taken up ; the remainder was fibrin of silk. 

 When silk is distilled with dilute sulphuric acid a peculiar acid comes 

 over in minute quantities, which Mulder terms bombic acid. The 

 constituents of yellow silk are — fibrin of silk 53-37, gelatin 20*66, 

 albumen 24*43, cerin 1*39, colouring matter 0*05, fat and resin 0*10. 

 — Poggendorff's Annalen, xxxvii. 594. 



IX, — Analysis of Phosphate of Lead. By Dr. R. D. Thomson. 



This specimen was from Lead Hills. Sp. Gr. 6*631. 

 Its constituents are- 

 Chlorine 2-656 



Lead 7*668 



Protoxide of Lead .... 69*636 



Phosphoric acid .... 17*626 



Protoxide of iron .... 2*008 



Water 0*800 



Silica 0*400 



100*794 



X. — Effect of Alkalies (J'c. on Vegetables. 



The following has been forwarded by a correspondent : — 

 " During last summer I performed a series of experiments with a 

 view to ascertain what effect various substances had in supporting 

 vegetable growth; for this purpose I procured several plants and 

 placed them in vessels of water, adding to each various proportions 

 of the alkalis, salts and other matters. Now, I found that more than 

 one thousandth part of potassa, soda or their salts, would prove in- 

 jurious, rendering the plant sickly or destroying it according to the 

 strength of the solution. By adding a thousandth part I found the 

 plant invigorated and decidedly more healthy than those parts which 

 were in water alone ; some of these plants existed in these vehicles 

 for six or eight weeks, and, to all appearance, would longer had I 

 prolonged the experiment ; but they required renewing with the 

 stimulcnts after the space of 12, 24, or 36 hours, according to the 



