All Children Touched Function Not Working?

So...in my script what I have is a model with several parts and a script. This script is suppose to make it so that if any of these parts gets hit, then the following function will occur. The output error I am getting is as follows...

23:06:43.724 - Touched is not a valid member of Script 23:06:43.724 - Script 'Workspace.Model.Script', Line 21 23:06:43.724 - Stack End

Here is the script...

for i, child in pairs (script.Parent:GetChildren()) do
    if child:IsA("BasePart") then -- consider only the Parts of the model    
		function onTouch(hit)
		local human = hit.Parent:findFirstChild("Humanoid")
			if (human ~= nil) then
				while (human ~= nil) do
				local s = wait(1)
				local health = human.Health
				if health > 0 and health < human.MaxHealth then
					local newHealthDelta = 0.01 * s * human.MaxHealth
					health = health + newHealthDelta
					human.Health = math.min(health,human.MaxHealth)
				end
				end
					if human.Health > human.MaxHealth then
				human.Health = human.MaxHealth
			end
			end
		end
		end
connection = child.Touched:connect(onTouch)
end

Your line 21 is not included in the check that child:IsA("BasePart"); so you have a Script which is a child, but Script objects do not have a Touched property.

Move line 21 into the condition to make sure it is a BasePart, ensuring it has a Touched property.

You should really retab your code, too.

for i, child in pairs (script.Parent:GetChildren()) do
	if child:IsA("BasePart") then -- consider only the Parts of the model    
		function onTouch(hit)
			local human = hit.Parent:findFirstChild("Humanoid")
			if (human ~= nil) then
				while (human ~= nil) do
					local s = wait(1)
					local health = human.Health
					if health > 0 and health < human.MaxHealth then
						local newHealthDelta = 0.01 * s * human.MaxHealth
						health = health + newHealthDelta
						human.Health = math.min(health,human.MaxHealth)
					end
				end
				if human.Health > human.MaxHealth then
					human.Health = human.MaxHealth
				end
			end
		end
		connection = child.Touched:connect(onTouch)
	end
end

Note that the assignment to connection (on your line 21, my line 20) is redundant since it would be overridden repeatedly by the loop. Since you aren't using it, you shouldn't include it in your code - it could be confusing.

Like in good writing, every element of a script should have a clear purpose.