If you get stuck, here are hints and solutions to all the puzzles.
WARNING this contains many spoilers.

This room is linear meaning one puzzle leads to the next.

The Toy Chest:
1: Look at the top of the toy chest. Have you seen these items before?
2: Rabbit, Train, Horse
Solution: code is 1,3,4 (1 rabbit mask, 3 train parts, 4 horses on wall)

The Owl and the Eagle:
1: There are buttons on the large owl and eagle statues
2: The chapters on the page are book titles
Solution: press sequence; owl, eagle, eagle, owl, owl

Frederik’s chamber:
1: use instruction note and book on stand to learn more
2: X means closed and O means open
Solution: Open IGNIS, pour red bottle into praeteritum, set spin dial to praeteritum, open FUMUS. Now walk into the open portal

Emily’s chamber:
1: The secret door is missing the pull lever
2: Perhaps one of the tools can help
Solution: take the door lever from the tool table and place it on the slot next to the door

Getting RUBY plant fibers:
1: The red ruby plants are ok, so they can be harvested
2: Perhaps a tool can be used
Solution: take garden pliers from the tool table and use them on the red flower at the gold plate with a plier symbol. now red petals should fall onto the plate

The plant energy converter:
1: follow the instructions above the converter
2: if you need fire, there is a lit candle on the machine in the center of the room
Solution: use the candle to light the candle in the converter, place ruby petals on the tray above, place an empty bottle from the cabinet left on the gold circle left of the candle. Now you get a red bottle to use in the machine

Getting away from Augustin’s chamber:
1: Augustin has hidden his last bottle in a familiar place
2: perhaps a safe chest, where you have been before
Solution: The green bottle is in the toy chest with same code 1,3,4

Can't get the machine to work?: You need to light the fire in the fireplace with the candle you found in Emily's chamber

The green house:
1: Read Emily’s notes on the box near her plants carefully. And take the plans she has made for the green house
2: She wants to go back and change the planning, but she can’t. Can you?
Solution: Take Emily’s plans for the green house and go to Augustin’s building. Here, place the plans on his work bench near the page stating “plans for building”.

The next FUTURUM bottle:
1: Perhaps Emily finally got her green house?
2: With the green plants thriving, you should be able to harvest them
Solution: Use the garden pliers again on the green plants near the gold plate with a symbol of pliers on it. Green leaves should fall on the plate when used. These go in the converter as before with the red leaves.

The last FUTURUM bottle:
1: The last bottle is in the cabinet in Frederik’s chamber
2: Emily broke the key, but the cabinets are from Augustin’s time
Solution: Go to Augustin’s chamber and get the key from the cabinet. This key works on the cabinet in all times and gives you the last green bottle

Please let me know if you need more hints or still get stuck anywhere.