How to calculate percent composition

To calculate percent composition of an element in a compound you multiply the number of atoms of the desired element, multiply by it's atomic weight, divide that by the formula mass of the compound and then multiply by 100. Very simple.

Book, what book?

For my glog I am reading The Knife Man, by Wendy Moore. This book covers a turning point in medical history as a one man surgical revolution takes on Georgian Europe with his daring and unconventional methods. This book details the scientific methods used by John Hunter, as well as the lengths he went to achieve greater understanding of surgery and  the human body. In a time when mortality rates associated with surgery were sky high, Hunter achieved an anatomical understanding that surpassed any of his day. Although I did not choose this book myself, I find the mix of intriguing story line history and scientific background to be most refreshing. After beginning this book, I am very glad that I did not grow up in the 1700's, where, if I was lucky enough to grow up, I may have had to risk a surgery with only a stiff shot of alcohol, while conscious, bleeding to death as an incompetent surgeon blundered around. 

Old & New Materials

   Function and form.... that's exactly what it is. Both qualities shared by modern engineered silk and the ancient samurai sword. The samurai sword performs it's function so well because of it's masterful composition. Silk as it has been, and as it is being engineered now is the same. This material is being called upon to perform a function optimally. Form to function, sounds a lot like biology, but that idea is more universal than that. The way that we have been able to take this material and apply its properties to perform optimal functions exemplifies the very spirit of chemistry. The samurai sword is the embodiment of perfection on that note. The use of materials for it's very creation is wondrous. In order to create this ancient marvel, blacksmiths had to understand the qualities of metal, and use them to their best effect. Thus they created the curved blade, that was neither too hard, nor too tough. They harnessed the very nature of the substance with which they were playing to satisfy their design requirements. This is the scientific spirit with which silk is now being explored, we are discovering it's properties in order to further function. Sustainable and biodegradable, edible and implantable silk as a technological material sounds like a foreign idea. Although it has been around for ages we are now using it to satisfy our current design requirements. We can use it to locally administer medicine, waste less, and create better technology. It is the perfect harmony between the product and the material that is characteristic of the most incredible feats of engineering that connect these two things. They are beautiful in their practicality.