Already have an account? Get multiple benefits of using own account!
Login in your account..!
Remember me
Don't have an account? Create your account in less than a minutes,
Forgot password? how can I recover my password now!
Enter right registered email to receive password!
Fire and Cookery :
Fire and Cookery where and when fiie came to be used is not known. Fire, to start with, must have been a frightening thing, giving rise to many myths and legends. However, as man slowly learned to control it, he found it very useful to keep himself wann and to frighten away wild animals. It is easy to imagine that chance eating of burnt or charred flesh must have led to the idea of cooking, which then made even tough meat edible and tastier. Thus, it must havetremendously increased the number of things one could eat. It was, perhaps, from the use offire for cooking that fired clay pottery and melting of metals for making tools arose.
Boiling gave rise to certain difficulties. At first, water was heated by dropping hot stones into water in leather buckets. We find such itones, cracked by heating and chilling, around prehistoric sites. The crucial discovery, however, was that by coating a basket with thick clay it could be put on the fire. Eventually, towards the end of the Stone Age. it was -discovered that coated baskets crack while heating, whereas pots made of heat-treated clay do not crack. Fired pottery was, tlrerel'ore, a very significant discovery. l.'inally, as Lhc problem of storing liquids for long periods in clay pots was tackled, the slower chemical changes of fermentation could be noted and later used for brewing wine. From the use of dyes, paints and tanning as found in this epoch, we can infer that the use of rudimentary chemistry for transforking materials was also in progress in the later part of the Stone Age.
Q. Mention chemical agents available for sterilization? Various chemical agents available for sterilization are: Alcohols: ethyl alcohol, isopropyl alcohol, trichlorobuta
Method to Estimate Phytochrome Since there is no chemical test, the only method available to test and estimate phytochrome is the spectrophotometric method. Firstly, the diffe
how many species of protozoan?
what are the general characters of nonchordates, explain
Amphibian frog embryo
In humans, maleness or femaleness is determined by a pair of sex chromosomes called X and Y. (a) What is the genotype for males? (b) What is the genot
Enumerate different implant materials with their pros and cons Biomaterials fall into four categories: metal and metal alloys, ceramics (carbon included in this group) syntheti
If you have water, 10% sucrose, and 40% sucrose solution. Which solutions were isotonic to each other?
Ritonavir (RTV, Norvir) Ritonavir is well absorbed from the gastrointestinal tract and at full doses potently inhibits HIV, but due to poor tolerability it is now used mainly
Valves of the Heart There are four valves which are flap-like structures that function to maintain unidirectional (forward) blood flow through the heart chambers. These va
Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!
whatsapp: +91-977-207-8620
Phone: +91-977-207-8620
Email: [email protected]
All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd