Causes on Low Testosterone in Men and Women! Zinc, B12, and Carnitine are critical. #testosterone #testosteronetherapy #testosteronelevels | Dan Purser MD

1.8M views · 46K reactions | The history of #photography Began with...

The history of #photography Began with the discovery of two critical principles: The first is camera obscura image projection, the second is the discovery that some substances are visibly altered by exposure to light [2]. There are no artifacts or descriptions that indicate any attempt to capture images with light sensitive materials prior to the 18tBegan with the discovery of two critical principles: The first is camera obscura image projection, the second is the discovery that some substances