Uh-huh, great.
Well firstky street brown comes in different strengths. Why? Coz it probably been exported from Afghanistan in some blokes ass, then bought by a wholesaler who has cut it with God knows what.... glucose, strichnine, who knows? Then in turn thats been bought by another dealer, and another. By the time your friend has it 8/9 people have probably mixed it down. Or 20 or 2, who knows?
So it's impossible to tell HOW much you need.
Heroin is evil, pure and simple. I speak from personal experience and I have lost a couple of friends to it and probably the best relationship I have ever had. If you need it to try out of curiousity I can tell you the buzz is no better than a good pill.
Also, you will be puking for hours after it, and it may well make you constipated.
If you are determined to do it, just try a little bit, about a third or less of the tic tak and see how you respond.
For educational purposes only:- What you do is you measure some water into the syringe, the amout you wanna inject, put some citric acid(about the same amount of H you are using) powder on the spoon. Now push the water onto the spoon, heat the water with a lighter and add the H. Stir it, still with the heat source but don't let it boil. Eventually you will see the H has dissolved. Now put the spoon carefully on the table. Get a cigarette filter cut a small bit off. This acts as a filter that will hopefully take some of the crap out when you draw it up. Get your works(syringe and needle) and draw it up. There you go. You have now got something that has ruined countless lifes and ended many more prematurley. Well do with it what you will.
To anyone that thinks it was stupid telling him how to do it, I would rather have the kid do it properly then make a fuck up and give himself a DVT or worse.